diff --git a/client/ayon_core/tools/push_to_project/models/integrate.py b/client/ayon_core/tools/push_to_project/models/integrate.py
index 08fafcbf2d..c512d3ef68 100644
--- a/client/ayon_core/tools/push_to_project/models/integrate.py
+++ b/client/ayon_core/tools/push_to_project/models/integrate.py
@@ -1153,10 +1153,10 @@ class ProjectPushItemProcess:
                 {"active": False}
             )
 
-    def _copy_version_thumbnail(self):
+    def _copy_version_thumbnail(self) -> Optional[str]:
         thumbnail_id = self._src_version_entity["thumbnailId"]
         if not thumbnail_id:
-            return
+            return None
         path = get_thumbnail_path(
             self._item.src_project_name,
             "version",
@@ -1164,7 +1164,7 @@ class ProjectPushItemProcess:
             thumbnail_id
         )
         if not path:
-            return
+            return None
         return ayon_api.create_thumbnail(
             self._item.dst_project_name,
             path