diff --git a/mininet/clean.py b/mininet/clean.py
index f2e4375e..b36a551b 100755
--- a/mininet/clean.py
+++ b/mininet/clean.py
@@ -61,7 +61,10 @@ def cleanup( cls):
         sh( 'killall -9 ' + zombies + ' 2> /dev/null' )
 
         # And kill off sudo mnexec
-        sh( 'pkill -9 -f "sudo mnexec"')
+        sh( 'pkill -9 -f "sudo mnexec"' )
+
+        # And kill off mn, mn doesn't exit when start twice "mn".
+        sh( 'pkill -9 -f "mn"' )
 
         info( "*** Removing junk from /tmp\n" )
         sh( 'rm -f /tmp/vconn* /tmp/vlogs* /tmp/*.out /tmp/*.log' )