diff --git a/DDG4/include/DDG4/IoStreams.h b/DDG4/include/DDG4/IoStreams.h
index 89333e80dc43ae8ab71a5e6724246a8d6dbfc181..af045ae003bf85f5114a89d7e506af212e5e2f2a 100644
--- a/DDG4/include/DDG4/IoStreams.h
+++ b/DDG4/include/DDG4/IoStreams.h
@@ -109,7 +109,7 @@ namespace DD4hep {
     /// Native stream handle
     handle_type       m_handle = 0;
     /// Stream flag(s)
-    dd4hep_file_flags m_flag = 0;
+    dd4hep_file_flags m_flag = close_handle;
   };