diff --git a/util/versioncheck.py b/util/versioncheck.py
index cdf6c22..7180f49 100755
--- a/util/versioncheck.py
+++ b/util/versioncheck.py
@@ -8,7 +8,7 @@ version = 'Mininet ' + co( 'PYTHONPATH=. bin/mn --version', shell=True )
 version = version.strip()
 
 # Find all Mininet path references
-lines = co( "grep -or 'Mininet \w\.\w\.\w[\w\+]*' *", shell=True )
+lines = co( "grep -or 'Mininet \w\+\.\w\+\.\w\+[+]*' *", shell=True )
 
 error = False