diff --git a/InvenTree/InvenTree/models.py b/InvenTree/InvenTree/models.py
index e8430694d0..be5de69be1 100644
--- a/InvenTree/InvenTree/models.py
+++ b/InvenTree/InvenTree/models.py
@@ -184,7 +184,7 @@ def FilterChildren(queryset, parent):
 
     if not parent:
         return queryset
-    elif isinstance(parent, str) and parent.lower() in ['none', 'false', 'null', 'top', '0']:
+    elif str(parent).lower() in ['none', 'false', 'null', 'top', '0']:
         return queryset.filter(parent=None)
     else:
         try: