--- a/tests/test-http-bad-server.t	Mon Mar 02 15:34:51 2020 -0500
+++ b/tests/test-http-bad-server.t	Tue Feb 25 20:27:39 2020 -0500
@@ -15,6 +15,8 @@
   > sparse-revlog = no
   > [devel]
   > legacy.exchange = phases
+  > [server]
+  > concurrent-push-mode = strict
   > EOF
 
   $ hg init server0