diff --git a/.ci/cirrus.runner.yml b/.ci/cirrus.runner.yml
index b0fb881..d97d15e 100644
--- a/.ci/cirrus.runner.yml
+++ b/.ci/cirrus.runner.yml
@@ -1,5 +1,6 @@
 task:
   name: "Update Runner Image ($MACOS_VERSION)"
+  execution_lock: runner-image-update
   env:
     matrix:
       - MACOS_VERSION: sonoma