diff --git a/k4MarlinWrapper/k4MarlinWrapper/LcioEventAlgo.h b/k4MarlinWrapper/k4MarlinWrapper/LcioEventAlgo.h
index c60db683..db006d47 100644
--- a/k4MarlinWrapper/k4MarlinWrapper/LcioEventAlgo.h
+++ b/k4MarlinWrapper/k4MarlinWrapper/LcioEventAlgo.h
@@ -42,7 +42,7 @@ class LcioEvent : public Gaudi::Algorithm {
   Gaudi::Property<std::vector<std::string>> m_fileNames{this, "Files", {}};
   MT::LCReader*                             m_reader = nullptr;
   int                                       m_numberOfEvents{};
-  mutable int                               m_currentEvent{};
+  mutable int                               m_currentEvent{};  // No atomicity necessary since not re-entrant
   bool                                      isReEntrant() const final { return false; }
 };