diff --git a/examples/controllers.py b/examples/controllers.py
index 1fcefb1..d3694bc 100755
--- a/examples/controllers.py
+++ b/examples/controllers.py
@@ -29,8 +29,7 @@ class MultiSwitch( OVSSwitch ):
 topo = TreeTopo( depth=2, fanout=2 )
 net = Mininet( topo=topo, switch=MultiSwitch, build=False )
 for c in [ c0, c1 ]:
-	net.addController(c)
-
+    net.addController(c)
 net.build()
 net.start()
 CLI( net )