diff --git a/smach/src/smach/state_machine.py b/smach/src/smach/state_machine.py
index 6223d39..dcfb61f 100644
--- a/smach/src/smach/state_machine.py
+++ b/smach/src/smach/state_machine.py
@@ -73,7 +73,7 @@ def __init__(self, outcomes, input_keys=[], output_keys=[]):
 
     ### Getter and Setter to allow pickling and unpickling state machines
     def __getstate__(self):
-        return {k:v for (k, v) in self.__dict__.items() if k is not "_state_transitioning_lock"}
+        return {k:v for (k, v) in self.__dict__.items() if k != "_state_transitioning_lock"}
 
     def __setstate__(self, d):
         self.__dict__ = d