diff --git a/examples/nested.proto b/examples/nested.proto
index 5689c03..cea61d2 100644
--- a/examples/nested.proto
+++ b/examples/nested.proto
@@ -12,4 +12,4 @@ message OuterMessage {
   string important_string = 1 [(validator.field) = {regex: "^[a-z]{2,5}$"}];
   // proto3 doesn't have `required`, the `msg_exist` enforces presence of InnerMessage.
   InnerMessage inner = 2 [(validator.field) = {msg_exists : true}];
-}
\ No newline at end of file
+}
diff --git a/examples/uuid.pb.go b/examples/uuid.pb.go
new file mode 100644
index 0000000..175dd07
--- /dev/null
+++ b/examples/uuid.pb.go
@@ -0,0 +1,81 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: examples/uuid.proto
+
+package validator_examples
+
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	_ "github.com/mwitkow/go-proto-validators"
+	math "math"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
+
+type UUIDMsg struct {
+	// user_id must be a valid version 4 UUID.
+	UserId               string   `protobuf:"bytes,1,opt,name=user_id,json=userId,proto3" json:"user_id,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *UUIDMsg) Reset()         { *m = UUIDMsg{} }
+func (m *UUIDMsg) String() string { return proto.CompactTextString(m) }
+func (*UUIDMsg) ProtoMessage()    {}
+func (*UUIDMsg) Descriptor() ([]byte, []int) {
+	return fileDescriptor_0029f00507e892b3, []int{0}
+}
+
+func (m *UUIDMsg) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_UUIDMsg.Unmarshal(m, b)
+}
+func (m *UUIDMsg) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_UUIDMsg.Marshal(b, m, deterministic)
+}
+func (m *UUIDMsg) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_UUIDMsg.Merge(m, src)
+}
+func (m *UUIDMsg) XXX_Size() int {
+	return xxx_messageInfo_UUIDMsg.Size(m)
+}
+func (m *UUIDMsg) XXX_DiscardUnknown() {
+	xxx_messageInfo_UUIDMsg.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_UUIDMsg proto.InternalMessageInfo
+
+func (m *UUIDMsg) GetUserId() string {
+	if m != nil {
+		return m.UserId
+	}
+	return ""
+}
+
+func init() {
+	proto.RegisterType((*UUIDMsg)(nil), "validator.examples.UUIDMsg")
+}
+
+func init() { proto.RegisterFile("examples/uuid.proto", fileDescriptor_0029f00507e892b3) }
+
+var fileDescriptor_0029f00507e892b3 = []byte{
+	// 144 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0x4e, 0xad, 0x48, 0xcc,
+	0x2d, 0xc8, 0x49, 0x2d, 0xd6, 0x2f, 0x2d, 0xcd, 0x4c, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17,
+	0x12, 0x2a, 0x4b, 0xcc, 0xc9, 0x4c, 0x49, 0x2c, 0xc9, 0x2f, 0xd2, 0x83, 0x49, 0x4b, 0x99, 0xa5,
+	0x67, 0x96, 0x64, 0x94, 0x26, 0xe9, 0x25, 0xe7, 0xe7, 0xea, 0xe7, 0x96, 0x67, 0x96, 0x64, 0xe7,
+	0x97, 0xeb, 0xa7, 0xe7, 0xeb, 0x82, 0x35, 0xe8, 0xc2, 0xd5, 0x17, 0xeb, 0x23, 0xb4, 0x82, 0xa5,
+	0x94, 0x74, 0xb9, 0xd8, 0x43, 0x43, 0x3d, 0x5d, 0x7c, 0x8b, 0xd3, 0x85, 0x94, 0xb8, 0xd8, 0x4b,
+	0x8b, 0x53, 0x8b, 0xe2, 0x33, 0x53, 0x24, 0x18, 0x15, 0x18, 0x35, 0x38, 0x9d, 0x38, 0x1f, 0xdd,
+	0x97, 0x67, 0x8d, 0x60, 0x9c, 0xc0, 0xc8, 0x12, 0xc4, 0x06, 0x92, 0xf1, 0x4c, 0x49, 0x62, 0x03,
+	0xeb, 0x32, 0x06, 0x04, 0x00, 0x00, 0xff, 0xff, 0xbc, 0x56, 0xba, 0x22, 0x98, 0x00, 0x00, 0x00,
+}
diff --git a/examples/uuid.proto b/examples/uuid.proto
new file mode 100644
index 0000000..05d61ed
--- /dev/null
+++ b/examples/uuid.proto
@@ -0,0 +1,8 @@
+syntax = "proto3";
+package validator.examples;
+import "github.com/mwitkow/go-proto-validators/validator.proto";
+
+message UUIDMsg {
+  // user_id must be a valid version 4 UUID.
+  string user_id = 1 [(validator.field) = {uuid_ver: 4, string_not_empty: true}];
+}
diff --git a/examples/uuid.validator.pb.go b/examples/uuid.validator.pb.go
new file mode 100644
index 0000000..b2652af
--- /dev/null
+++ b/examples/uuid.validator.pb.go
@@ -0,0 +1,30 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: examples/uuid.proto
+
+package validator_examples
+
+import (
+	fmt "fmt"
+	math "math"
+	proto "github.com/golang/protobuf/proto"
+	_ "github.com/mwitkow/go-proto-validators"
+	regexp "regexp"
+	github_com_mwitkow_go_proto_validators "github.com/mwitkow/go-proto-validators"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+var _regex_UUIDMsg_UserId = regexp.MustCompile(`^([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[4][a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12})?$`)
+
+func (this *UUIDMsg) Validate() error {
+	if !_regex_UUIDMsg_UserId.MatchString(this.UserId) {
+		return github_com_mwitkow_go_proto_validators.FieldError("UserId", fmt.Errorf(`value '%v' must be a string conforming to regex "^([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[4][a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12})?$"`, this.UserId))
+	}
+	if this.UserId == "" {
+		return github_com_mwitkow_go_proto_validators.FieldError("UserId", fmt.Errorf(`value '%v' must not be an empty string`, this.UserId))
+	}
+	return nil
+}
diff --git a/plugin/plugin.go b/plugin/plugin.go
index 6a7e394..60c20eb 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -57,12 +57,18 @@ import (
 
 	"github.com/gogo/protobuf/gogoproto"
 	"github.com/gogo/protobuf/proto"
-	descriptor "github.com/gogo/protobuf/protoc-gen-gogo/descriptor"
+	"github.com/gogo/protobuf/protoc-gen-gogo/descriptor"
 	"github.com/gogo/protobuf/protoc-gen-gogo/generator"
 	"github.com/gogo/protobuf/vanity"
 	validator "github.com/mwitkow/go-proto-validators"
 )
 
+const uuidPattern = "^([a-fA-F0-9]{8}-" +
+	"[a-fA-F0-9]{4}-" +
+	"[%s][a-fA-F0-9]{3}-" +
+	"[8|9|aA|bB][a-fA-F0-9]{3}-" +
+	"[a-fA-F0-9]{12})?$"
+
 type plugin struct {
 	*generator.Generator
 	generator.PluginImports
@@ -154,9 +160,21 @@ func (p *plugin) generateRegexVars(file *generator.FileDescriptor, message *gene
 	ccTypeName := generator.CamelCaseSlice(message.TypeName())
 	for _, field := range message.Field {
 		validator := getFieldValidatorIfAny(field)
-		if validator != nil && validator.Regex != nil {
+		if validator != nil {
 			fieldName := p.GetOneOfFieldName(message, field)
-			p.P(`var `, p.regexName(ccTypeName, fieldName), ` = `, p.regexPkg.Use(), `.MustCompile(`, "`", *validator.Regex, "`", `)`)
+			if validator.Regex != nil && validator.UuidVer != nil {
+				fmt.Fprintf(os.Stderr, "WARNING: regex and uuid validator is set for field %v.%v, only one of them can be set. Regex and UUID validator is ignored for this field.", ccTypeName, fieldName)
+			} else if validator.UuidVer != nil {
+				uuid, err := getUUIDRegex(validator.UuidVer)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "WARNING: field %v.%v error %s.\n", ccTypeName, fieldName, err)
+				} else {
+					validator.Regex = &uuid
+					p.P(`var `, p.regexName(ccTypeName, fieldName), ` = `, p.regexPkg.Use(), `.MustCompile(`, "`", *validator.Regex, "`", `)`)
+				}
+			} else if validator.Regex != nil {
+				p.P(`var `, p.regexName(ccTypeName, fieldName), ` = `, p.regexPkg.Use(), `.MustCompile(`, "`", *validator.Regex, "`", `)`)
+			}
 		}
 	}
 }
@@ -500,8 +518,32 @@ func (p *plugin) generateFloatValidator(variableName string, ccTypeName string,
 	}
 }
 
+// getUUIDRegex returns a regex to validate that a string is in UUID
+// format. The version parameter specified the UUID version. If version is 0,
+// the returned regex is valid for any UUID version
+func getUUIDRegex(version *int32) (string, error) {
+	if version == nil {
+		return "", nil
+	} else if *version < 0 || *version > 5 {
+		return "", fmt.Errorf("UUID version should be between 0-5, Got %d", *version)
+	} else if *version == 0 {
+		return fmt.Sprintf(uuidPattern, "1-5"), nil
+	} else {
+		return fmt.Sprintf(uuidPattern, strconv.Itoa(int(*version))), nil
+	}
+}
+
 func (p *plugin) generateStringValidator(variableName string, ccTypeName string, fieldName string, fv *validator.FieldValidator) {
-	if fv.Regex != nil {
+	if fv.Regex != nil || fv.UuidVer != nil {
+		if fv.UuidVer != nil {
+			uuid, err := getUUIDRegex(fv.UuidVer)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "WARNING: field %v.%v error %s.\n", ccTypeName, fieldName, err)
+			} else {
+				fv.Regex = &uuid
+			}
+		}
+
 		p.P(`if !`, p.regexName(ccTypeName, fieldName), `.MatchString(`, variableName, `) {`)
 		p.In()
 		errorStr := "be a string conforming to regex " + strconv.Quote(fv.GetRegex())
diff --git a/test/gogo/validator_test.go b/test/gogo/validator_test.go
index e556665..25b8306 100644
--- a/test/gogo/validator_test.go
+++ b/test/gogo/validator_test.go
@@ -4,6 +4,7 @@
 package validatortest
 
 import (
+	fmt "fmt"
 	"strings"
 	"testing"
 
@@ -14,8 +15,16 @@ var (
 	stableBytes = make([]byte, 12)
 )
 
-func buildProto3(someString string, someInt uint32, identifier string, someValue int64, someDoubleStrict float64,
-	someFloatStrict float32, someDouble float64, someFloat float32, nonEmptyString string, repeatedCount uint32, someStringLength string, someBytes []byte) *ValidatorMessage3 {
+const (
+	uuid4 = "fbe91ff5-fee7-40d3-89a8-f3db6cf210be"
+	uuid1 = "66bb25e2-2e0d-11e9-b210-d663bd873d93"
+)
+
+func buildProto3(someString string, someInt uint32, identifier string,
+	someValue int64, someDoubleStrict float64, someFloatStrict float32, someDouble float64,
+	someFloat float32, nonEmptyString string, repeatedCount uint32,
+	someStringLength string, someBytes []byte,
+	optionalUUIDAny, uuid4 string) *ValidatorMessage3 {
 	goodEmbeddedProto3 := &ValidatorMessage3_Embedded{
 		Identifier: identifier,
 		SomeValue:  someValue,
@@ -60,6 +69,9 @@ func buildProto3(someString string, someInt uint32, identifier string, someValue
 		SomeBytesGtReq:   someBytes,
 		SomeBytesEqReq:   someBytes,
 		RepeatedBaseType: []int32{},
+
+		UUIDAny:       optionalUUIDAny,
+		UUID4NotEmpty: uuid4,
 	}
 
 	goodProto3.Repeated = make([]int32, repeatedCount)
@@ -67,8 +79,11 @@ func buildProto3(someString string, someInt uint32, identifier string, someValue
 	return goodProto3
 }
 
-func buildProto2(someString string, someInt uint32, identifier string, someValue int64, someDoubleStrict float64,
-	someFloatStrict float32, someDouble float64, someFloat float32, nonEmptyString string, repeatedCount uint32, someStringLength string, someBytes []byte) *ValidatorMessage {
+func buildProto2(someString string, someInt uint32, identifier string,
+	someValue int64, someDoubleStrict float64, someFloatStrict float32, someDouble float64,
+	someFloat float32, nonEmptyString string, repeatedCount uint32,
+	someStringLength string, someBytes []byte,
+	optionalUUIDAny, uuid5 string) *ValidatorMessage {
 	goodEmbeddedProto2 := &ValidatorMessage_Embedded{
 		Identifier: &identifier,
 		SomeValue:  &someValue,
@@ -120,6 +135,9 @@ func buildProto2(someString string, someInt uint32, identifier string, someValue
 		SomeBytesGtReq:   someBytes,
 		SomeBytesEqReq:   someBytes,
 		RepeatedBaseType: []int32{},
+
+		UUIDAny:       &optionalUUIDAny,
+		UUID4NotEmpty: &uuid5,
 	}
 
 	goodProto2.Repeated = make([]int32, repeatedCount)
@@ -129,7 +147,7 @@ func buildProto2(someString string, someInt uint32, identifier string, someValue
 
 func TestGoodProto3(t *testing.T) {
 	var err error
-	goodProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	goodProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	err = goodProto3.Validate()
 	if err != nil {
 		t.Fatalf("unexpected fail in validator: %v", err)
@@ -138,7 +156,7 @@ func TestGoodProto3(t *testing.T) {
 
 func TestGoodProto2(t *testing.T) {
 	var err error
-	goodProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	goodProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	err = goodProto2.Validate()
 	if err != nil {
 		t.Fatalf("unexpected fail in validator: %v", err)
@@ -146,254 +164,254 @@ func TestGoodProto2(t *testing.T) {
 }
 
 func TestStringRegex(t *testing.T) {
-	tooLong1Proto3 := buildProto3("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong1Proto3 := buildProto3("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if tooLong1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong2Proto3 := buildProto3("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong2Proto3 := buildProto3("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if tooLong2Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong1Proto2 := buildProto2("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong1Proto2 := buildProto2("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if tooLong1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong2Proto2 := buildProto2("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong2Proto2 := buildProto2("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if tooLong2Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestIntLowerBounds(t *testing.T) {
-	lowerThan10Proto3 := buildProto3("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan10Proto3 := buildProto3("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan10Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan10Proto2 := buildProto2("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan10Proto2 := buildProto2("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan10Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestIntUpperBounds(t *testing.T) {
-	greaterThan100Proto3 := buildProto3("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan100Proto3 := buildProto3("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan100Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan100Proto2 := buildProto2("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan100Proto2 := buildProto2("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan100Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestDoubleStrictLowerBounds(t *testing.T) {
-	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan035EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan035EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan035EpsilonProto3.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
-	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan035EpsilonProto2.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
 }
 
 func TestDoubleStrictUpperBounds(t *testing.T) {
-	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan065EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan065EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan065EpsilonProto3.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
-	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan065EpsilonProto2.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
 }
 
 func TestFloatStrictLowerBounds(t *testing.T) {
-	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan035EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan035EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := greaterThan035EpsilonProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := greaterThan035EpsilonProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatStrictUpperBounds(t *testing.T) {
-	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan065EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if greaterThan065EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := lowerThan065EpsilonProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := lowerThan065EpsilonProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestDoubleNonStrictLowerBounds(t *testing.T) {
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestDoubleNonStrictUpperBounds(t *testing.T) {
-	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if higherThan1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if higherThan1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatNonStrictLowerBounds(t *testing.T) {
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatNonStrictUpperBounds(t *testing.T) {
-	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if higherThan1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if higherThan1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestStringNonEmpty(t *testing.T) {
-	emptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes)
+	emptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if emptyStringProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	emptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes)
+	emptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if emptyStringProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	nonEmptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	nonEmptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := nonEmptyStringProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	nonEmptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	nonEmptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := nonEmptyStringProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestRepeatedEltsCount(t *testing.T) {
-	notEnoughEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes)
+	notEnoughEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes, uuid1, uuid4)
 	if notEnoughEltsProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	notEnoughEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes)
+	notEnoughEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes, uuid1, uuid4)
 	if notEnoughEltsProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooManyEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes)
+	tooManyEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes, uuid1, uuid4)
 	if tooManyEltsProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooManyEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes)
+	tooManyEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes, uuid1, uuid4)
 	if tooManyEltsProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	validEltsCountProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	validEltsCountProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := validEltsCountProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	validEltsCountProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	validEltsCountProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	if err := validEltsCountProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestMsgExist(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	someProto3.SomeEmbedded = nil
 	if err := someProto3.Validate(); err != nil {
 		t.Fatalf("validate shouldn't fail on missing SomeEmbedded, not annotated")
@@ -407,7 +425,7 @@ func TestMsgExist(t *testing.T) {
 }
 
 func TestNestedError3(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	someProto3.SomeEmbeddedExists.SomeValue = 101 // should be less than 101
 	if err := someProto3.Validate(); err == nil {
 		t.Fatalf("expected fail due to nested SomeEmbeddedExists.SomeValue being wrong")
@@ -417,7 +435,7 @@ func TestNestedError3(t *testing.T) {
 }
 
 func TestCustomError_Proto3(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	someProto3.CustomErrorInt = 30
 	expectedErr := "invalid field CustomErrorInt: My Custom Error"
 	if err := someProto3.Validate(); err == nil {
@@ -516,3 +534,58 @@ func TestOneOf_Regex(t *testing.T) {
 	err = example.Validate()
 	assert.NoError(t, err, "This message should pass all validation")
 }
+
+func TestUUID4Validation(t *testing.T) {
+	testcases := []struct {
+		uuid string
+		fail bool
+	}{
+		{
+			uuid: uuid1,
+			fail: true,
+		},
+
+		{
+			uuid: uuid4,
+			fail: false,
+		},
+
+		{
+			uuid: "",
+			fail: true,
+		},
+
+		{
+			uuid: "66bb25e2-2e0d",
+			fail: true,
+		},
+
+		{
+			uuid: "1234abcd",
+			fail: true,
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(fmt.Sprintf("proto2 uuid '%s'", tc.uuid), func(t *testing.T) {
+			msg := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, tc.uuid)
+
+			err := msg.Validate()
+			failed := err != nil
+			if tc.fail != failed {
+				t.Errorf("Expected validation failure: %t, but got %t, err: %v", tc.fail, failed, err)
+			}
+		})
+
+		t.Run(fmt.Sprintf("proto3 uuid '%s'", tc.uuid), func(t *testing.T) {
+			msg := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, tc.uuid)
+
+			err := msg.Validate()
+			failed := err != nil
+			if tc.fail != failed {
+				t.Errorf("Expected validation failure: %t, but got %t, err: %v", tc.fail, failed, err)
+			}
+		})
+
+	}
+}
diff --git a/test/golang/validator_test.go b/test/golang/validator_test.go
index d088075..cc14907 100644
--- a/test/golang/validator_test.go
+++ b/test/golang/validator_test.go
@@ -4,6 +4,7 @@
 package validatortest
 
 import (
+	fmt "fmt"
 	"strings"
 	"testing"
 
@@ -14,9 +15,15 @@ var (
 	stableBytes = make([]byte, 12)
 )
 
+const (
+	uuid4 = "fbe91ff5-fee7-40d3-89a8-f3db6cf210be"
+	uuid1 = "66bb25e2-2e0d-11e9-b210-d663bd873d93"
+)
+
 func buildProto3(someString string, someInt uint32, identifier string, someValue int64, someDoubleStrict float64,
 	someFloatStrict float32, someDouble float64, someFloat float32, nonEmptyString string, repeatedCount uint32,
-	someStringLength string, someBytes []byte) *ValidatorMessage3 {
+	someStringLength string, someBytes []byte,
+	optionalUUIDAny, uuid4 string) *ValidatorMessage3 {
 	goodEmbeddedProto3 := &ValidatorMessage3_Embedded{
 		Identifier: identifier,
 		SomeValue:  someValue,
@@ -62,6 +69,9 @@ func buildProto3(someString string, someInt uint32, identifier string, someValue
 		SomeBytesEqReq: someBytes,
 
 		RepeatedBaseType: []int32{},
+
+		UUIDAny:       optionalUUIDAny,
+		UUID4NotEmpty: uuid4,
 	}
 
 	goodProto3.Repeated = make([]int32, repeatedCount)
@@ -69,7 +79,11 @@ func buildProto3(someString string, someInt uint32, identifier string, someValue
 	return goodProto3
 }
 
-func buildProto2(someString string, someInt uint32, identifier string, someValue int64, someDoubleStrict float64, someFloatStrict float32, someDouble float64, someFloat float32, nonEmptyString string, repeatedCount uint32, someStringLength string, someBytes []byte) *ValidatorMessage {
+func buildProto2(someString string, someInt uint32, identifier string,
+	someValue int64, someDoubleStrict float64, someFloatStrict float32, someDouble float64,
+	someFloat float32, nonEmptyString string, repeatedCount uint32,
+	someStringLength string, someBytes []byte,
+	optionalUUIDAny, uuid5 string) *ValidatorMessage {
 	goodEmbeddedProto2 := &ValidatorMessage_Embedded{
 		Identifier: &identifier,
 		SomeValue:  &someValue,
@@ -120,6 +134,9 @@ func buildProto2(someString string, someInt uint32, identifier string, someValue
 		SomeBytesGtReq:     someBytes,
 		SomeBytesEqReq:     someBytes,
 		RepeatedBaseType:   []int32{},
+
+		UUIDAny:       &optionalUUIDAny,
+		UUID4NotEmpty: &uuid5,
 	}
 
 	goodProto2.Repeated = make([]int32, repeatedCount)
@@ -129,7 +146,7 @@ func buildProto2(someString string, someInt uint32, identifier string, someValue
 
 func TestGoodProto3(t *testing.T) {
 	var err error
-	goodProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	goodProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
 	err = goodProto3.Validate()
 	if err != nil {
 		t.Fatalf("unexpected fail in validator: %v", err)
@@ -138,7 +155,8 @@ func TestGoodProto3(t *testing.T) {
 
 func TestGoodProto2(t *testing.T) {
 	var err error
-	goodProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	goodProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	err = goodProto2.Validate()
 	if err != nil {
 		t.Fatalf("unexpected fail in validator: %v", err)
@@ -146,254 +164,307 @@ func TestGoodProto2(t *testing.T) {
 }
 
 func TestStringRegex(t *testing.T) {
-	tooLong1Proto3 := buildProto3("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong1Proto3 := buildProto3("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooLong1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong2Proto3 := buildProto3("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong2Proto3 := buildProto3("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooLong2Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong1Proto2 := buildProto2("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong1Proto2 := buildProto2("toolong", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooLong1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooLong2Proto2 := buildProto2("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	tooLong2Proto2 := buildProto2("-%ab", 11, "bad#", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooLong2Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestIntLowerBounds(t *testing.T) {
-	lowerThan10Proto3 := buildProto3("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan10Proto3 := buildProto3("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan10Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan10Proto2 := buildProto2("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan10Proto2 := buildProto2("-%ab", 9, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan10Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", -1, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestIntUpperBounds(t *testing.T) {
-	greaterThan100Proto3 := buildProto3("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan100Proto3 := buildProto3("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan100Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan100Proto2 := buildProto2("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan100Proto2 := buildProto2("-%ab", 11, "abba", 101, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan100Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
 }
 
 func TestDoubleStrictLowerBounds(t *testing.T) {
-	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan035EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.3, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan035EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan035EpsilonProto3.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
-	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.300000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan035EpsilonProto2.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
 }
 
 func TestDoubleStrictUpperBounds(t *testing.T) {
-	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan065EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.70000000001, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan065EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan065EpsilonProto3.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
-	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.6999999999, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan065EpsilonProto2.Validate() != nil {
 		t.Fatalf("unexpected fail in validator")
 	}
 }
 
 func TestFloatStrictLowerBounds(t *testing.T) {
-	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan035EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.2999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan035EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := greaterThan035EpsilonProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan035EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.3000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := greaterThan035EpsilonProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatStrictUpperBounds(t *testing.T) {
-	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan065EpsilonProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	greaterThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.7000001, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if greaterThan065EpsilonProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := lowerThan065EpsilonProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan065EpsilonProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.6999999, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := lowerThan065EpsilonProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestDoubleNonStrictLowerBounds(t *testing.T) {
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.2499999, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.25, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestDoubleNonStrictUpperBounds(t *testing.T) {
-	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if higherThan1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75111111, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if higherThan1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.75, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatNonStrictLowerBounds(t *testing.T) {
-	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes)
+	lowerThan0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.2499999, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if lowerThan0Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.25, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestFloatNonStrictUpperBounds(t *testing.T) {
-	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if higherThan1Proto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes)
+	higherThan1Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75111111, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if higherThan1Proto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes)
+	equalTo0Proto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.75, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := equalTo0Proto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestStringNonEmpty(t *testing.T) {
-	emptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes)
+	emptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if emptyStringProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	emptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes)
+	emptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if emptyStringProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	nonEmptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	nonEmptyStringProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := nonEmptyStringProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	nonEmptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	nonEmptyStringProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := nonEmptyStringProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestRepeatedEltsCount(t *testing.T) {
-	notEnoughEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes)
+	notEnoughEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes, uuid1, uuid4)
+
 	if notEnoughEltsProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	notEnoughEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes)
+	notEnoughEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 1, "1234567890", stableBytes, uuid1, uuid4)
+
 	if notEnoughEltsProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooManyEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes)
+	tooManyEltsProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooManyEltsProto3.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	tooManyEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes)
+	tooManyEltsProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 14, "1234567890", stableBytes, uuid1, uuid4)
+
 	if tooManyEltsProto2.Validate() == nil {
 		t.Fatalf("expected fail in validator, but it didn't happen")
 	}
-	validEltsCountProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	validEltsCountProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := validEltsCountProto3.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
-	validEltsCountProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	validEltsCountProto2 := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := validEltsCountProto2.Validate(); err != nil {
 		t.Fatalf("unexpected fail in validator %v", err)
 	}
 }
 
 func TestMsgExist(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	someProto3.SomeEmbedded = nil
 	if err := someProto3.Validate(); err != nil {
 		t.Fatalf("validate shouldn't fail on missing SomeEmbedded, not annotated")
@@ -407,31 +478,36 @@ func TestMsgExist(t *testing.T) {
 }
 
 func TestStringLengthValidator(t *testing.T) {
-	StringLengthErrorProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "abc456", stableBytes)
+	StringLengthErrorProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "abc456", stableBytes, uuid1, uuid4)
+
 	if err := StringLengthErrorProto3.Validate(); err == nil {
 		t.Fatalf("validate shouldn't fail on error length")
 	}
 
-	StringLengthSuccess := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	StringLengthSuccess := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := StringLengthSuccess.Validate(); err != nil {
 		t.Fatalf("validate shouldn't fail on equal length")
 	}
 }
 
 func TestBytesLengthValidator(t *testing.T) {
-	StringLengthErrorProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "abc456", []byte("anc"))
+	StringLengthErrorProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "abc456", []byte("anc"), uuid1, uuid4)
+
 	if err := StringLengthErrorProto3.Validate(); err == nil {
 		t.Fatalf("validate shouldn't fail on error length")
 	}
 
-	StringLengthSuccess := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	StringLengthSuccess := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	if err := StringLengthSuccess.Validate(); err != nil {
 		t.Fatalf("validate shouldn't fail on equal length")
 	}
 }
 
 func TestNestedError3(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	someProto3.SomeEmbeddedExists.SomeValue = 101 // should be less than 101
 	if err := someProto3.Validate(); err == nil {
 		t.Fatalf("expected fail due to nested SomeEmbeddedNonNullable.SomeValue being wrong")
@@ -441,7 +517,8 @@ func TestNestedError3(t *testing.T) {
 }
 
 func TestCustomError_Proto3(t *testing.T) {
-	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes)
+	someProto3 := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, uuid4)
+
 	someProto3.CustomErrorInt = 30
 	expectedErr := "invalid field CustomErrorInt: My Custom Error"
 	if err := someProto3.Validate(); err == nil {
@@ -540,3 +617,58 @@ func TestOneOf_Regex(t *testing.T) {
 	err = example.Validate()
 	assert.NoError(t, err, "This message should pass all validation")
 }
+
+func TestUUID4Validation(t *testing.T) {
+	testcases := []struct {
+		uuid string
+		fail bool
+	}{
+		{
+			uuid: uuid1,
+			fail: true,
+		},
+
+		{
+			uuid: uuid4,
+			fail: false,
+		},
+
+		{
+			uuid: "",
+			fail: true,
+		},
+
+		{
+			uuid: "66bb25e2-2e0d",
+			fail: true,
+		},
+
+		{
+			uuid: "1234abcd",
+			fail: true,
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(fmt.Sprintf("proto2 uuid '%s'", tc.uuid), func(t *testing.T) {
+			msg := buildProto2("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, tc.uuid)
+
+			err := msg.Validate()
+			failed := err != nil
+			if tc.fail != failed {
+				t.Errorf("Expected validation failure: %t, but got %t, err: %v", tc.fail, failed, err)
+			}
+		})
+
+		t.Run(fmt.Sprintf("proto3 uuid '%s'", tc.uuid), func(t *testing.T) {
+			msg := buildProto3("-%ab", 11, "abba", 99, 0.5, 0.5, 0.5, 0.5, "x", 4, "1234567890", stableBytes, uuid1, tc.uuid)
+
+			err := msg.Validate()
+			failed := err != nil
+			if tc.fail != failed {
+				t.Errorf("Expected validation failure: %t, but got %t, err: %v", tc.fail, failed, err)
+			}
+		})
+
+	}
+}
diff --git a/test/validator_proto2.proto b/test/validator_proto2.proto
index e0e95ae..95fab52 100644
--- a/test/validator_proto2.proto
+++ b/test/validator_proto2.proto
@@ -70,9 +70,11 @@ message ValidatorMessage {
 
 	optional string SomeStringLtReq = 36 [(validator.field) = {length_gt: 2}];
 	optional string SomeStringGtReq = 37 [(validator.field) = {length_lt: 12}];
-    optional string SomeStringEqReq = 38 [(validator.field) = {length_eq: 10}];
+	optional string SomeStringEqReq = 38 [(validator.field) = {length_eq: 10}];
 	optional bytes SomeBytesLtReq = 39 [(validator.field) = {length_gt: 5}];
 	optional bytes SomeBytesGtReq = 40 [(validator.field) = {length_lt: 20}];
 	optional bytes SomeBytesEqReq = 41 [(validator.field) = {length_eq: 12}];
 
+	optional string UUIDAny = 42 [(validator.field) = {uuid_ver: 0}];
+	required string UUID4NotEmpty = 43 [(validator.field) = {uuid_ver: 4, string_not_empty: true}];
 }
diff --git a/test/validator_proto3.proto b/test/validator_proto3.proto
index dd0b9dd..0257d45 100644
--- a/test/validator_proto3.proto
+++ b/test/validator_proto3.proto
@@ -69,4 +69,7 @@ message ValidatorMessage3 {
 	bytes SomeBytesLtReq = 39 [(validator.field) = {length_gt: 5}];
 	bytes SomeBytesGtReq = 40 [(validator.field) = {length_lt: 20}];
 	bytes SomeBytesEqReq = 41 [(validator.field) = {length_eq: 12}];
+
+	string UUIDAny = 42 [(validator.field) = {uuid_ver: 0}];
+	string UUID4NotEmpty = 43 [(validator.field) = {uuid_ver: 4, string_not_empty: true}];
 }
diff --git a/validator.pb.go b/validator.pb.go
index 28aa675..b2befcf 100644
--- a/validator.pb.go
+++ b/validator.pb.go
@@ -65,7 +65,11 @@ type FieldValidator struct {
 	// Field value of integer strictly equal this value.
 	LengthEq *int64 `protobuf:"varint,16,opt,name=length_eq,json=lengthEq" json:"length_eq,omitempty"`
 	// Requires that the value is in the enum.
-	IsInEnum             *bool    `protobuf:"varint,17,opt,name=is_in_enum,json=isInEnum" json:"is_in_enum,omitempty"`
+	IsInEnum *bool `protobuf:"varint,17,opt,name=is_in_enum,json=isInEnum" json:"is_in_enum,omitempty"`
+	// Ensures that a string value is in UUID format.
+	// uuid_ver specifies the valid UUID versions. Valid values are: 0-5.
+	// If uuid_ver is 0 all UUID versions are accepted.
+	UuidVer              *int32   `protobuf:"varint,18,opt,name=uuid_ver,json=uuidVer" json:"uuid_ver,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -214,6 +218,13 @@ func (m *FieldValidator) GetIsInEnum() bool {
 	return false
 }
 
+func (m *FieldValidator) GetUuidVer() int32 {
+	if m != nil && m.UuidVer != nil {
+		return *m.UuidVer
+	}
+	return 0
+}
+
 type OneofValidator struct {
 	// Require that one of the oneof fields is set.
 	Required             *bool    `protobuf:"varint,1,opt,name=required" json:"required,omitempty"`
@@ -281,34 +292,35 @@ func init() {
 func init() { proto.RegisterFile("validator.proto", fileDescriptor_bf1c6ec7c0d80dd5) }
 
 var fileDescriptor_bf1c6ec7c0d80dd5 = []byte{
-	// 454 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x6c, 0x93, 0xcf, 0x6b, 0xd4, 0x40,
-	0x14, 0xc7, 0x89, 0xed, 0xb6, 0xc9, 0xdb, 0x76, 0x5b, 0x07, 0x85, 0x69, 0xb5, 0x18, 0xea, 0x25,
-	0x87, 0x92, 0x82, 0x47, 0x8f, 0x4a, 0x5c, 0x84, 0xd5, 0x4a, 0x0e, 0x1e, 0xbc, 0x84, 0xd8, 0xbc,
-	0x4d, 0x07, 0x26, 0x33, 0xd9, 0x99, 0x17, 0x59, 0xff, 0x1f, 0xff, 0x4b, 0x15, 0x64, 0x26, 0x66,
-	0x93, 0xc2, 0x1e, 0xe7, 0xf3, 0x79, 0xf9, 0xce, 0x0f, 0xbe, 0x81, 0xb3, 0x1f, 0xa5, 0x14, 0x55,
-	0x49, 0xda, 0xa4, 0xad, 0xd1, 0xa4, 0x59, 0xb4, 0x03, 0x97, 0x71, 0xad, 0x75, 0x2d, 0xf1, 0xd6,
-	0x8b, 0xef, 0xdd, 0xfa, 0xb6, 0x42, 0x7b, 0x6f, 0x44, 0xbb, 0x1b, 0xbe, 0xfe, 0x75, 0x08, 0x8b,
-	0x0f, 0x02, 0x65, 0xf5, 0x75, 0xf8, 0x88, 0x3d, 0x83, 0x99, 0xc1, 0x1a, 0xb7, 0x3c, 0x88, 0x83,
-	0x24, 0xca, 0xfb, 0x05, 0x7b, 0x0e, 0x47, 0x42, 0x51, 0x51, 0x13, 0x7f, 0x12, 0x07, 0xc9, 0x41,
-	0x3e, 0x13, 0x8a, 0x96, 0x34, 0x60, 0x49, 0xfc, 0x60, 0x87, 0x57, 0xc4, 0xae, 0x00, 0x1a, 0x5b,
-	0x17, 0xb8, 0x15, 0x96, 0x2c, 0x3f, 0x8c, 0x83, 0x24, 0xcc, 0xa3, 0xc6, 0xd6, 0x99, 0x07, 0xec,
-	0x15, 0xcc, 0x1f, 0xba, 0xa6, 0x54, 0x05, 0x1a, 0xa3, 0x0d, 0x9f, 0xf9, 0x8d, 0xc0, 0xa3, 0xcc,
-	0x11, 0x76, 0x01, 0xe1, 0x5a, 0xea, 0xd2, 0xef, 0x77, 0x14, 0x07, 0x49, 0x90, 0x1f, 0xfb, 0xf5,
-	0x92, 0x46, 0x25, 0x89, 0x1f, 0x4f, 0xd4, 0x8a, 0xd8, 0x6b, 0x38, 0xed, 0x15, 0xb6, 0x56, 0x48,
-	0xad, 0x78, 0xe8, 0xfd, 0x89, 0x87, 0x59, 0xcf, 0xd8, 0x0b, 0x88, 0x86, 0x68, 0xe4, 0x91, 0x1f,
-	0x08, 0xff, 0x67, 0xe3, 0x28, 0x25, 0x21, 0x87, 0x89, 0x5c, 0x11, 0xb2, 0x04, 0xce, 0x2d, 0x19,
-	0xa1, 0xea, 0x42, 0x69, 0x2a, 0xb0, 0x69, 0xe9, 0x27, 0x9f, 0xfb, 0xab, 0x2d, 0x7a, 0xfe, 0x59,
-	0x53, 0xe6, 0x28, 0xbb, 0x01, 0x66, 0xb0, 0xc5, 0x92, 0xb0, 0x2a, 0xee, 0x75, 0xa7, 0xa8, 0x68,
-	0x84, 0xe2, 0x27, 0xfe, 0x85, 0xce, 0x07, 0xf3, 0xde, 0x89, 0x4f, 0x42, 0xed, 0x9b, 0x2e, 0xb7,
-	0xfc, 0x74, 0xdf, 0x74, 0xb9, 0x75, 0x47, 0x94, 0xa8, 0x6a, 0x7a, 0x70, 0x6f, 0xb3, 0xf0, 0x43,
-	0x61, 0x0f, 0x96, 0x34, 0x91, 0x92, 0xf8, 0xd9, 0x54, 0xae, 0xa6, 0x12, 0x37, 0xfc, 0x7c, 0x2a,
-	0xb3, 0x0d, 0x7b, 0x09, 0x20, 0x6c, 0x21, 0x54, 0x81, 0xaa, 0x6b, 0xf8, 0x53, 0x7f, 0xad, 0x50,
-	0xd8, 0x8f, 0x2a, 0x53, 0x5d, 0x73, 0x7d, 0x03, 0x8b, 0x3b, 0x85, 0x7a, 0x3d, 0xb6, 0xe4, 0x12,
-	0x42, 0x83, 0x9b, 0x4e, 0x18, 0xac, 0x7c, 0x51, 0xc2, 0x7c, 0xb7, 0x7e, 0xfb, 0x05, 0x66, 0x6b,
-	0xd7, 0x29, 0x76, 0x95, 0xf6, 0x05, 0x4c, 0x87, 0x02, 0xa6, 0xbe, 0x6b, 0x77, 0x2d, 0x09, 0xad,
-	0x2c, 0xff, 0xf3, 0xdb, 0x95, 0x66, 0xfe, 0xe6, 0x22, 0x1d, 0x3b, 0xfc, 0xb8, 0x8c, 0x79, 0x1f,
-	0xe4, 0x12, 0xb5, 0xdb, 0x7f, 0x4f, 0xa2, 0x3f, 0xd7, 0x90, 0xf8, 0x77, 0x4f, 0xe2, 0xe3, 0x83,
-	0xe7, 0x7d, 0xd0, 0xbb, 0xf9, 0xb7, 0xf1, 0x3f, 0xf9, 0x17, 0x00, 0x00, 0xff, 0xff, 0x95, 0xab,
-	0x34, 0x60, 0x44, 0x03, 0x00, 0x00,
+	// 472 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x6c, 0x93, 0x41, 0x6f, 0xd4, 0x30,
+	0x10, 0x85, 0x15, 0xda, 0xb4, 0x89, 0xb7, 0xdd, 0x2e, 0x16, 0x48, 0x6e, 0xa1, 0x22, 0x2a, 0x97,
+	0x1c, 0xaa, 0x54, 0xe2, 0xc8, 0x11, 0x14, 0x56, 0x48, 0x0b, 0x45, 0x39, 0xf4, 0xc0, 0xc5, 0x0a,
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+	0xb2, 0x49, 0xa5, 0x3d, 0xce, 0xfb, 0x26, 0x6f, 0xc6, 0xa3, 0x17, 0x72, 0xf6, 0x58, 0x4a, 0x51,
+	0x95, 0xa8, 0x4d, 0xd6, 0x1a, 0x8d, 0x9a, 0xc6, 0x3b, 0xe1, 0x22, 0xa9, 0xb5, 0xae, 0x25, 0xdc,
+	0x78, 0xf0, 0xa3, 0x5b, 0xdf, 0x54, 0x60, 0xef, 0x8d, 0x68, 0x77, 0xcd, 0x57, 0xbf, 0x0e, 0xc9,
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+	0x90, 0xc6, 0x45, 0x5f, 0xd0, 0x97, 0xe4, 0x48, 0x28, 0xe4, 0x35, 0xb2, 0x67, 0x49, 0x90, 0x1e,
+	0x14, 0xa1, 0x50, 0xb8, 0xc4, 0x41, 0x96, 0xc8, 0x0e, 0x76, 0xf2, 0x0a, 0xe9, 0x25, 0x21, 0x8d,
+	0xad, 0x39, 0x6c, 0x85, 0x45, 0xcb, 0x0e, 0x93, 0x20, 0x8d, 0x8a, 0xb8, 0xb1, 0x75, 0xee, 0x05,
+	0xfa, 0x86, 0xcc, 0x1e, 0xba, 0xa6, 0x54, 0x1c, 0x8c, 0xd1, 0x86, 0x85, 0x7e, 0x10, 0xf1, 0x52,
+	0xee, 0x14, 0x7a, 0x4e, 0xa2, 0xb5, 0xd4, 0xa5, 0x9f, 0x77, 0x94, 0x04, 0x69, 0x50, 0x1c, 0xfb,
+	0x7a, 0x89, 0x23, 0x92, 0xc8, 0x8e, 0x27, 0x68, 0x85, 0xf4, 0x2d, 0x39, 0xed, 0x11, 0xb4, 0x56,
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+	0x7d, 0x43, 0xf4, 0xdf, 0x1b, 0x46, 0x28, 0x11, 0x18, 0x99, 0xc0, 0x15, 0x02, 0x4d, 0xc9, 0xc2,
+	0xa2, 0x11, 0xaa, 0xe6, 0x4a, 0x23, 0x87, 0xa6, 0xc5, 0x9f, 0x6c, 0xe6, 0x9f, 0x36, 0xef, 0xf5,
+	0xaf, 0x1a, 0x73, 0xa7, 0xd2, 0x6b, 0x42, 0x0d, 0xb4, 0x50, 0x22, 0x54, 0xfc, 0x5e, 0x77, 0x0a,
+	0x79, 0x23, 0x14, 0x3b, 0xf1, 0x17, 0x5a, 0x0c, 0xe4, 0xa3, 0x03, 0x5f, 0x84, 0xda, 0xd7, 0x5d,
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+	0x85, 0xf9, 0x86, 0xbe, 0x26, 0x44, 0x58, 0x2e, 0x14, 0x07, 0xd5, 0x35, 0xec, 0xb9, 0x7f, 0x56,
+	0x24, 0xec, 0x67, 0x95, 0xab, 0xae, 0x71, 0x47, 0xef, 0x3a, 0x51, 0xf1, 0x47, 0x30, 0x8c, 0x26,
+	0x41, 0x1a, 0x16, 0xc7, 0xae, 0xbe, 0x03, 0x73, 0x75, 0x4d, 0xe6, 0xb7, 0x0a, 0xf4, 0x7a, 0x0c,
+	0xd0, 0x05, 0x89, 0x0c, 0x6c, 0x3a, 0x61, 0xa0, 0xf2, 0x19, 0x8a, 0x8a, 0x5d, 0xfd, 0xfe, 0x1b,
+	0x09, 0xd7, 0x2e, 0x6e, 0xf4, 0x32, 0xeb, 0xb3, 0x99, 0x0d, 0xd9, 0xcc, 0x7c, 0x0c, 0x6f, 0x5b,
+	0x14, 0x5a, 0x59, 0xf6, 0xe7, 0xb7, 0xcb, 0xd3, 0xec, 0xdd, 0x79, 0x36, 0xc6, 0xfb, 0x69, 0x4e,
+	0x8b, 0xde, 0xc8, 0x39, 0x6a, 0x37, 0x7f, 0x8f, 0xa3, 0xdf, 0x6b, 0x70, 0xfc, 0xbb, 0xc7, 0xf1,
+	0xe9, 0xe2, 0x45, 0x6f, 0xf4, 0x61, 0xf6, 0x7d, 0xfc, 0x85, 0xfe, 0x05, 0x00, 0x00, 0xff, 0xff,
+	0x05, 0x20, 0x26, 0x13, 0x5f, 0x03, 0x00, 0x00,
 }
diff --git a/validator.proto b/validator.proto
index 6a82760..40a24e7 100644
--- a/validator.proto
+++ b/validator.proto
@@ -68,6 +68,10 @@ message FieldValidator {
   optional int64 length_eq = 16;
   // Requires that the value is in the enum.
   optional bool is_in_enum = 17;
+  // Ensures that a string value is in UUID format.
+  // uuid_ver specifies the valid UUID versions. Valid values are: 0-5.
+  // If uuid_ver is 0 all UUID versions are accepted.
+  optional int32 uuid_ver = 18;
 }
 
 message OneofValidator {