diff --git a/Event/EventContainers/src/InternalOfflineFast.cxx b/Event/EventContainers/src/InternalOfflineFast.cxx
index 118d7c1df88584e54a7b96db1241ef61829aad4b..4aaa02d53922433e4f51ed1a8af6e0cf86316c82 100644
--- a/Event/EventContainers/src/InternalOfflineFast.cxx
+++ b/Event/EventContainers/src/InternalOfflineFast.cxx
@@ -77,7 +77,7 @@ void InternalOfflineFast::cleanUp(deleter_f* deleter) noexcept {
     }
     else {
       for(size_t i=0 ;i < m_fullMap.size(); ++i){
-         if(m_fullMap[i]) deleter(m_fullMap[i]);
+         if(m_fullMap[i]) { deleter(m_fullMap[i]); m_fullMap[i] = nullptr; }
       }
     }
     m_map.clear();