diff --git a/mininet/util.py b/mininet/util.py
index 673d3f6dc192e8fff479c4461eca1a10f9a6b6b9..b1dc4920e9d3b4cdb51789431babeca1045e28b9 100644
--- a/mininet/util.py
+++ b/mininet/util.py
@@ -253,7 +253,7 @@ def macColonHex( mac ):
     """Generate MAC colon-hex string from unsigned int.
        mac: MAC address as unsigned int
        returns: macStr MAC colon-hex string"""
-       return _colonHex( mac, 6 )
+    return _colonHex( mac, 6 )
 
 def ipStr( ip ):
     """Generate IP address string from an unsigned int.