diff --git a/product/ERP5Type/patches/OFSFolder.py b/product/ERP5Type/patches/OFSFolder.py
index 030299036b443e67b96c5294fd956d03ae6d3d74..fd0293908f93032cbc6b084f60476b7036214959 100644
--- a/product/ERP5Type/patches/OFSFolder.py
+++ b/product/ERP5Type/patches/OFSFolder.py
@@ -52,6 +52,6 @@ def Folder_isERP5SitePresent(self):
       usefull to identify if a erp5 is present already on a Zope
       Setup.
   """
-  return len(self.objectIds("ERP5 Site")) > 1
+  return len(self.objectIds("ERP5 Site")) > 0
 
 Folder.isERP5SitePresent = Folder_isERP5SitePresent