diff --git a/stack/erp5/buildout.cfg b/stack/erp5/buildout.cfg
index b5e9419a14f47404ba8237e51df91cc0c5ac2fca..e6788ed6594b8dff7ca8f7a4eb33b596c089096f 100644
--- a/stack/erp5/buildout.cfg
+++ b/stack/erp5/buildout.cfg
@@ -4,7 +4,7 @@ develop =
   ${:parts-directory}/slapos.cookbook-repository
   ${:parts-directory}/cloudooo-repository
 
-find-links =
+find-links +=
   http://www.owlfish.com/software/wsgiutils/download.html
 
 extends =