diff --git a/tests/serial_failover.py b/tests/serial_failover.py
index fab5141..ffbbf0a 100644
--- a/tests/serial_failover.py
+++ b/tests/serial_failover.py
@@ -84,7 +84,7 @@
                 time.sleep(1)
                 count = count + 1
         else:
-            self.assertTrue(false, "Unknown controller kill method")
+            self.assertTrue(False, "Unknown controller kill method")
 
     def buildControllerList(self):
         # controller_list is list of ip/port tuples