diff --git a/.github/mergify.yml b/.github/mergify.yml
index 1cbbf39..5fafc19 100644
--- a/.github/mergify.yml
+++ b/.github/mergify.yml
@@ -5,7 +5,7 @@
 # to dedup some of the check-x=y repetition in the future.
 queue_rules:
   - name: default
-    conditions:
+    queue_conditions:
       - check-success=checks
       - check-success=check-commits
       - check-success=build-server (default, centos, amd64)
@@ -127,3 +127,6 @@ pull_request_rules:
       label:
         add:
           - "priority-review"
+
+merge_queue:
+  max_parallel_checks: 1