diff --git a/src/isValid.ts b/src/isValid.ts
index b0b04fd..003cbd1 100644
--- a/src/isValid.ts
+++ b/src/isValid.ts
@@ -53,7 +53,7 @@ function isValidLiteral(schema: LiteralSchema, value: any): boolean {
 }
 
 function isValidObject(schema: ObjectSchema, value: any): boolean {
-  if (typeof value !== 'object') {
+  if (typeOf(value) !== 'object') {
     return false
   }
 
diff --git a/src/object.test.ts b/src/object.test.ts
index 3937867..deed039 100644
--- a/src/object.test.ts
+++ b/src/object.test.ts
@@ -94,4 +94,12 @@ test(`object marks optional fields by ending keys with ?`, function () {
   assert.is(res3, true)
 })
 
+test(`null is not an object`, function () {
+  const obj = object({})
+
+  const res = isValid(obj, null)
+
+  assert.is(res, false)
+})
+
 test.run()