diff --git a/gitlab/v4/objects/__init__.py b/gitlab/v4/objects/__init__.py
index f9a2c25e6..0f9a6554f 100644
--- a/gitlab/v4/objects/__init__.py
+++ b/gitlab/v4/objects/__init__.py
@@ -1210,6 +1210,7 @@ class GroupMergeRequestManager(ListMixin, RESTManager):
         "source_branch",
         "target_branch",
         "search",
+        "wip",
     )
     _types = {"labels": types.ListAttribute}
 
@@ -1732,6 +1733,7 @@ class MergeRequestManager(ListMixin, RESTManager):
         "source_branch",
         "target_branch",
         "search",
+        "wip",
     )
     _types = {"labels": types.ListAttribute}