diff --git a/entc/gen/type.go b/entc/gen/type.go
index 56bac39c5..881dd2b58 100644
--- a/entc/gen/type.go
+++ b/entc/gen/type.go
@@ -125,11 +125,13 @@ func NewType(c Config, schema *load.Schema) (*Type, error) {
 		fields: make(map[string]*Field, len(schema.Fields)),
 	}
 	for i, f := range schema.Fields {
-		if !f.Type.Valid() {
+		switch {
+		case !f.Type.Valid():
 			return nil, fmt.Errorf("invalid type for field %s", f.Name)
-		}
-		if f.Nillable && !f.Optional {
+		case f.Nillable && !f.Optional:
 			return nil, fmt.Errorf("nillable field %q must be optional", f.Name)
+		case f.Unique && f.Default:
+			return nil, fmt.Errorf("unique field %q can not have default value", f.Name)
 		}
 		typ.Fields[i] = &Field{
 			def:        f,
diff --git a/entc/gen/type_test.go b/entc/gen/type_test.go
index 0a2c2018c..b2d5253f5 100644
--- a/entc/gen/type_test.go
+++ b/entc/gen/type_test.go
@@ -20,6 +20,14 @@ func TestType(t *testing.T) {
 	require.Equal("t1", typ.Label())
 	require.Equal("t1", typ.Package())
 	require.Equal("t", typ.Receiver())
+
+	typ, err = NewType(Config{Package: "entc/gen"}, &load.Schema{
+		Fields: []*load.Field{
+			{Unique: true, Default: true, Type: field.TypeInt},
+		},
+	})
+	require.Error(err, "unique field can not have default")
+	require.Nil(typ)
 }
 
 func TestType_Label(t *testing.T) {