diff --git a/zuul/executor/server.py b/zuul/executor/server.py
index b22be60..d739c18 100644
--- a/zuul/executor/server.py
+++ b/zuul/executor/server.py
@@ -1225,6 +1225,7 @@
             post_status, post_code = self.runAnsiblePlaybook(
                 playbook, args['timeout'], success, phase='post', index=index)
             if post_status != self.RESULT_NORMAL or post_code != 0:
+                success = False
                 # If we encountered a pre-failure, that takes
                 # precedence over the post result.
                 if not pre_failed: