diff --git a/mininet/cli.py b/mininet/cli.py
index 2ff9825..3df99ad 100644
--- a/mininet/cli.py
+++ b/mininet/cli.py
@@ -297,6 +297,7 @@ class CLI( Cmd ):
                     break
         except IOError:
             error( 'error reading file %s\n' % args[ 0 ] )
+        self.inputFile.close()
         self.inputFile = None
 
     def do_dpctl( self, line ):