diff --git a/Control/AthenaConfiguration/python/MainServicesConfig.py b/Control/AthenaConfiguration/python/MainServicesConfig.py
index 5ae6073308f84590b110fb94489074c4eecce72c..666aa64607dbc014a0b169ac85f2b92bcddfbd9d 100644
--- a/Control/AthenaConfiguration/python/MainServicesConfig.py
+++ b/Control/AthenaConfiguration/python/MainServicesConfig.py
@@ -22,9 +22,8 @@ def MainServicesMiniCfg(loopMgr='AthenaEventLoopMgr', masterSequence='AthAlgSeq'
     return cfg
 
 
-def MainServicesCfg(cfgFlags):
+def MainServicesCfg(cfgFlags, LoopMgr='AthenaEventLoopMgr'):
     # Run a serial job for threads=0
-    LoopMgr = 'AthenaEventLoopMgr'
     if cfgFlags.Concurrency.NumThreads>0:
         if cfgFlags.Concurrency.NumConcurrentEvents==0:
             # In a threaded job this will mess you up because no events will be processed