diff --git a/NPLib/Core/NPOptionManager.cxx b/NPLib/Core/NPOptionManager.cxx
index 682a47b1d7b37afd5acaf9e5fa42a5eb1d6d7234..93750b5313023ea998372acf5cff46b82758293c 100644
--- a/NPLib/Core/NPOptionManager.cxx
+++ b/NPLib/Core/NPOptionManager.cxx
@@ -107,6 +107,7 @@ void NPOptionManager::ReadTheInputArgument(int argc, char** argv){
   fRunToReadFileName          = fDefaultRunToReadFileName;
   fCalibrationFileName        = fDefaultCalibrationFileName;
   fG4MacroPath                = fDefaultG4MacroPath;
+  fIsSplit = false;
   fLastSimFile = false; 
   fLastPhyFile = false;
   fLastResFile = false;