diff --git a/itests/steps/marathon_steps.py b/itests/steps/marathon_steps.py
index <HASH>..<HASH> 100644
--- a/itests/steps/marathon_steps.py
+++ b/itests/steps/marathon_steps.py
@@ -158,7 +158,7 @@ def stop_listening_stream(context):
 
     # and 2 deployment_step_success events
     filtered_events = [e for e in context.events if e.event_type == "deployment_success"]
-    assert len(filtered_events) == 1
+    assert len(filtered_events) == 1, "We had %d filtered_events: %s" % (len(filtered_events), filtered_events)
 
 
 @then('we should be able to see a deployment')
Add some debug logic to the assert