diff --git a/CHANGELOG_PENDING.md b/CHANGELOG_PENDING.md
index 5e78e66..ca42e8b 100644
--- a/CHANGELOG_PENDING.md
+++ b/CHANGELOG_PENDING.md
@@ -2,4 +2,6 @@
 
 ### Bug Fixes
 
+- Fix panic in environment definition [#418](https://github.com/pulumi/pulumi-pulumiservice/issues/418)
+
 ### Miscellaneous
diff --git a/provider/pkg/provider/environment.go b/provider/pkg/provider/environment.go
index d2a7cbb..6526fb1 100644
--- a/provider/pkg/provider/environment.go
+++ b/provider/pkg/provider/environment.go
@@ -238,15 +238,20 @@ func (st *PulumiServiceEnvironmentResource) Check(req *pulumirpc.CheckRequest) (
 		}
 	}
 
-	yamlBytes := []byte{}
-	if !inputMap["yaml"].IsComputed() {
-		yamlBytes, err = getBytesFromAsset(inputMap["yaml"].AssetValue())
-		if err != nil {
-			return nil, err
+	var stringYaml string
+	inputYaml := inputMap["yaml"]
+	if !inputYaml.IsComputed() {
+		if inputYaml.IsAsset() {
+			yamlBytes, err := getBytesFromAsset(inputYaml.AssetValue())
+			if err != nil {
+				return nil, err
+			}
+			stringYaml = string(yamlBytes)
+		} else {
+			stringYaml = inputYaml.StringValue()
 		}
 	}
 
-	stringYaml := string(yamlBytes)
 	trimmedYaml := strings.TrimSpace(stringYaml)
 	inputMap["yaml"] = resource.MakeSecret(resource.NewStringProperty(trimmedYaml))