diff --git a/controller/state/changer.py b/controller/state/changer.py
index b23ddf7..0beacf3 100644
--- a/controller/state/changer.py
+++ b/controller/state/changer.py
@@ -24,7 +24,7 @@ class Changer(object):
             'closed': self.close_in_valve
         }
 
-    def stop_everything:
+    def stop_everything(self):
         self.close_in_valve
         self.close_out_valve