diff --git a/addons/web/http.py b/addons/web/http.py
index 988525b6b51..e0bd34a1bd0 100644
--- a/addons/web/http.py
+++ b/addons/web/http.py
@@ -563,7 +563,7 @@ class Root(object):
         controllers and configure them.  """
 
         for addons_path in openerp.modules.module.ad_paths:
-            for module in sorted(os.listdir(addons_path)):
+            for module in sorted(os.listdir(str(addons_path))):
                 if module not in addons_module:
                     manifest_path = os.path.join(addons_path, module, '__openerp__.py')
                     path_static = os.path.join(addons_path, module, 'static')