diff --git a/src/PMTSD.cc b/src/PMTSD.cc
index 7380caf3a8593f94b63c2646a195986cd3c9a1c6..ead1631bbfa2220c8da587a6083be4e9447cf44e 100644
--- a/src/PMTSD.cc
+++ b/src/PMTSD.cc
@@ -91,6 +91,8 @@ void PMTSD::Initialize(G4HCofThisEvent* HCE){
 
   m_nHits = 0;
 
+  for(auto vec : m_PtrVec ) vec->clear();
+
 }