diff --git a/PhysicsAnalysis/AnalysisCommon/PileupReweighting/share/generatePRW_jobOptions.py b/PhysicsAnalysis/AnalysisCommon/PileupReweighting/share/generatePRW_jobOptions.py
index 65955658a9457434efb34f81a2ff00b2e473a243..b9b642d05947b1c3acfa3cad9c81ac0b5704feba 100644
--- a/PhysicsAnalysis/AnalysisCommon/PileupReweighting/share/generatePRW_jobOptions.py
+++ b/PhysicsAnalysis/AnalysisCommon/PileupReweighting/share/generatePRW_jobOptions.py
@@ -14,7 +14,7 @@ if len(svcMgr.EventSelector.InputCollections)==0:
    
 
 #instantiate a tool without a config file, so that it's in config file making mode ...
-ToolSvc += CfgMgr.CP__PileupReweightingTool("auto",ConfigFiles=[],LumiCalcFiles=[],DataScaleFactor=1.0,DataScaleFactorUP=0.,DataScaleFactorDOWN=0.)
+ToolSvc += CfgMgr.CP__PileupReweightingTool("auto",ConfigFiles=[],LumiCalcFiles=[],DataScaleFactor=1.0,DataScaleFactorUP=0.,DataScaleFactorDOWN=0.,PeriodAssignments=[])
 
 #need to configure the weighttool to use TruthEvents, because of ATLASSIM-2989 bug in 20.7
 ToolSvc += CfgMgr.McEventWeight("MyWeights",UseTruthEvents=True)