diff --git a/product/ERP5/ERP5Site.py b/product/ERP5/ERP5Site.py
index d73d7287c23b096f96cc5aee693c4cf481d4c714..374093f048877c82922f61fdb5c6651e35747b91 100644
--- a/product/ERP5/ERP5Site.py
+++ b/product/ERP5/ERP5Site.py
@@ -111,7 +111,7 @@ def getCatalogStorageList(*args, **kw):
     #LOG('getCatalogStorageList', 0, item)
     if item == '.svn':
       continue
-    if item.endswith('.bt5') and os.path.isfile():
+    if item.endswith('.bt5') and os.path.isfile(item):
       # Simple heuristic to make it faster than extracting the whole bt
       if item.endswith('_catalog.bt5'):
         result.append((item, item))