diff --git a/buildbot/master/files/config/factories.py b/buildbot/master/files/config/factories.py
index c914be06..bab3a7be 100644
--- a/buildbot/master/files/config/factories.py
+++ b/buildbot/master/files/config/factories.py
@@ -41,7 +41,7 @@ def run(self):
                 )
             )
 
-        defer.returnValue(SUCCESS)
+        yield defer.returnValue(SUCCESS)
 
 
 class ServoFactory(util.BuildFactory):