diff --git a/website/helpers/product.py b/website/helpers/product.py
index 1e8257a..623ceee 100644
--- a/website/helpers/product.py
+++ b/website/helpers/product.py
@@ -102,4 +102,5 @@
 		
 def invalidate_cache_for(item_group):
 	for i in get_parent_item_groups(item_group):
-		delete_page_cache(i.page_name)
\ No newline at end of file
+		if i.page_name:
+			delete_page_cache(i.page_name)
\ No newline at end of file