diff --git a/PhysicsAnalysis/D3PDMaker/TruthD3PDMaker/src/PileUpInfoFillerTool.h b/PhysicsAnalysis/D3PDMaker/TruthD3PDMaker/src/PileUpInfoFillerTool.h
index 9c722667c2dce7307afd29ae1ca46c760793869f..b9557db5c64e3e3bd6dd15df59bf6536a88a3864 100644
--- a/PhysicsAnalysis/D3PDMaker/TruthD3PDMaker/src/PileUpInfoFillerTool.h
+++ b/PhysicsAnalysis/D3PDMaker/TruthD3PDMaker/src/PileUpInfoFillerTool.h
@@ -61,7 +61,7 @@ private:
   /// Variable: Event number.
   int* m_run_number;
   /// Variable: Run number.
-  uint64_t* m_event_number;
+  int* m_event_number;
   /// Write out Event Number
   bool  m_do_EvtNum;
 };