diff --git a/src/Mod/Part/AttachmentEditor/TaskAttachmentEditor.py b/src/Mod/Part/AttachmentEditor/TaskAttachmentEditor.py
index cd33e428a5..270d894c55 100644
--- a/src/Mod/Part/AttachmentEditor/TaskAttachmentEditor.py
+++ b/src/Mod/Part/AttachmentEditor/TaskAttachmentEditor.py
@@ -187,6 +187,12 @@ class AttachmentEditorTaskPanel(FrozenClass):
         self.callback_Apply     = callback_Apply
 
         self.obj = obj_to_attach
+        try:
+            if not self.obj.hasExtension('Part::AttachExtension'):
+                self.obj.addExtension('Part::AttachExtensionPython')
+        except Exception:
+            pass
+
         if hasattr(obj_to_attach,'Attacher'):
             self.attacher = obj_to_attach.Attacher
         elif hasattr(obj_to_attach,'AttacherType'):