diff --git a/xCAT/xCAT.spec b/xCAT/xCAT.spec
index cd525f1ae..8d350ed9d 100644
--- a/xCAT/xCAT.spec
+++ b/xCAT/xCAT.spec
@@ -19,6 +19,7 @@ Source4: prescripts.tar.gz
 %endif
 
 Provides: xCAT = %{version}
+Conflicts: xCATsn
 Requires: xCAT-server xCAT-client perl-DBD-SQLite
 
 %ifos linux
@@ -119,3 +120,7 @@ fi
 /install/postscripts
 /install/prescripts
 %defattr(-,root,root)
+%postun
+# removes MN file
+  rm /etc/xCATMN
+