diff --git a/zuul.d/image-build-jobs.yaml b/zuul.d/image-build-jobs.yaml
index fe75085..72690bd 100644
--- a/zuul.d/image-build-jobs.yaml
+++ b/zuul.d/image-build-jobs.yaml
@@ -1,3 +1,7 @@
+- semaphore:
+    name: opendev-build-arm64
+    max: 5
+
 - job:
     name: opendev-build-diskimage-base
     description: |