Index: trunk/MagicSoft/Mars/mfileio/MWriteRootFile.cc
===================================================================
--- trunk/MagicSoft/Mars/mfileio/MWriteRootFile.cc	(revision 9292)
+++ trunk/MagicSoft/Mars/mfileio/MWriteRootFile.cc	(revision 9302)
@@ -102,4 +102,5 @@
 
     gROOT->GetListOfCleanups()->Add(this); // To remove fOut if deleted
+    SetBit(kMustCleanup);
 }