diff --git a/lib/services/database.dart b/lib/services/database.dart
index 7b75f1c..1fd7b48 100644
--- a/lib/services/database.dart
+++ b/lib/services/database.dart
@@ -11,7 +11,7 @@ class Database extends Service {
      /// of the project's documents. [Learn more about different API
      /// modes](/docs/admin).
      ///
-    Future<Response> listDocuments({required String collectionId, List? filters, int? limit, int? offset, String? orderField, OrderType orderType = OrderType.asc, String? orderCast, String? search}) {
+    Future<Response> listDocuments({required String collectionId, List? filters, int? limit, int? offset, String? orderField, OrderType? orderType, String? orderCast, String? search}) {
         final String path = '/database/collections/{collectionId}/documents'.replaceAll(RegExp('{collectionId}'), collectionId);
 
         final Map<String, dynamic> params = {
@@ -19,7 +19,7 @@ class Database extends Service {
             'limit': limit,
             'offset': offset,
             'orderField': orderField,
-            'orderType': orderType.name(),
+            'orderType': orderType?.name(),
             'orderCast': orderCast,
             'search': search,
         };
diff --git a/lib/services/functions.dart b/lib/services/functions.dart
index 53a2817..30bec0e 100644
--- a/lib/services/functions.dart
+++ b/lib/services/functions.dart
@@ -11,14 +11,14 @@ class Functions extends Service {
      /// return a list of all of the project's executions. [Learn more about
      /// different API modes](/docs/admin).
      ///
-    Future<Response> listExecutions({required String functionId, String? search, int? limit, int? offset, OrderType orderType = OrderType.asc}) {
+    Future<Response> listExecutions({required String functionId, String? search, int? limit, int? offset, OrderType? orderType}) {
         final String path = '/functions/{functionId}/executions'.replaceAll(RegExp('{functionId}'), functionId);
 
         final Map<String, dynamic> params = {
             'search': search,
             'limit': limit,
             'offset': offset,
-            'orderType': orderType.name(),
+            'orderType': orderType?.name(),
         };
 
         final Map<String, String> headers = {
diff --git a/lib/services/storage.dart b/lib/services/storage.dart
index 7986721..d03cb0b 100644
--- a/lib/services/storage.dart
+++ b/lib/services/storage.dart
@@ -10,14 +10,14 @@ class Storage extends Service {
      /// your results. On admin mode, this endpoint will return a list of all of the
      /// project's files. [Learn more about different API modes](/docs/admin).
      ///
-    Future<Response> listFiles({String? search, int? limit, int? offset, OrderType orderType = OrderType.asc}) {
+    Future<Response> listFiles({String? search, int? limit, int? offset, OrderType? orderType}) {
         final String path = '/storage/files';
 
         final Map<String, dynamic> params = {
             'search': search,
             'limit': limit,
             'offset': offset,
-            'orderType': orderType.name(),
+            'orderType': orderType?.name(),
         };
 
         final Map<String, String> headers = {
diff --git a/lib/services/teams.dart b/lib/services/teams.dart
index aa5183b..913ed3d 100644
--- a/lib/services/teams.dart
+++ b/lib/services/teams.dart
@@ -11,14 +11,14 @@ class Teams extends Service {
      /// of the project's teams. [Learn more about different API
      /// modes](/docs/admin).
      ///
-    Future<Response> list({String? search, int? limit, int? offset, OrderType orderType = OrderType.asc}) {
+    Future<Response> list({String? search, int? limit, int? offset, OrderType? orderType}) {
         final String path = '/teams';
 
         final Map<String, dynamic> params = {
             'search': search,
             'limit': limit,
             'offset': offset,
-            'orderType': orderType.name(),
+            'orderType': orderType?.name(),
         };
 
         final Map<String, String> headers = {
@@ -110,14 +110,14 @@ class Teams extends Service {
      /// Get a team members by the team unique ID. All team members have read access
      /// for this list of resources.
      ///
-    Future<Response> getMemberships({required String teamId, String? search, int? limit, int? offset, OrderType orderType = OrderType.asc}) {
+    Future<Response> getMemberships({required String teamId, String? search, int? limit, int? offset, OrderType? orderType}) {
         final String path = '/teams/{teamId}/memberships'.replaceAll(RegExp('{teamId}'), teamId);
 
         final Map<String, dynamic> params = {
             'search': search,
             'limit': limit,
             'offset': offset,
-            'orderType': orderType.name(),
+            'orderType': orderType?.name(),
         };
 
         final Map<String, String> headers = {