diff --git a/callback_update.go b/callback_update.go
index e45a3a84..6c960723 100644
--- a/callback_update.go
+++ b/callback_update.go
@@ -37,6 +37,14 @@ func UpdateTimeStampWhenUpdate(scope *Scope) {
 	}
 }
 
+func escapeIfNeeded(scope *Scope, value string) string {
+	// default:'string value' OR  sql expression, like: default:"(now() at timezone 'utc')"
+	if (strings.HasPrefix(value, "'") && strings.HasSuffix(value, "'")) || (strings.HasPrefix(value, "(") && strings.HasSuffix(value, ")")) {
+		return value
+	}
+	return scope.AddToVars(value) // default:'something'  like:default:'false' should be between quotes (what AddToVars do)
+}
+
 func Update(scope *Scope) {
 	if !scope.HasError() {
 		var sqls []string
@@ -53,8 +61,8 @@ func Update(scope *Scope) {
 				if scope.changeableField(field) && !field.IsPrimaryKey && field.IsNormal {
 					if field.HasDefaultValue {
 						if field.IsBlank {
-							defaultValue := strings.Trim(parseTagSetting(field.Tag.Get("sql"))["DEFAULT"], "'")
-							sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(field.DBName), scope.AddToVars(defaultValue)))
+							defaultValue := parseTagSetting(field.Tag.Get("sql"))["DEFAULT"]
+							sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(field.DBName), escapeIfNeeded(scope, defaultValue)))
 						} else {
 							sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(field.DBName), scope.AddToVars(field.Field.Interface())))
 						}
diff --git a/create_test.go b/create_test.go
index 97175980..56ac19c2 100644
--- a/create_test.go
+++ b/create_test.go
@@ -51,7 +51,7 @@ func TestCreate(t *testing.T) {
 
 	DB.Model(user).Update("name", "create_user_new_name")
 	DB.First(&user, user.Id)
-	if user.CreatedAt != newUser.CreatedAt {
+	if user.CreatedAt.Format(time.RFC3339Nano) != newUser.CreatedAt.Format(time.RFC3339Nano) {
 		t.Errorf("CreatedAt should not be changed after update")
 	}
 }