diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index b3f1860f..4dd8be30 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -5,7 +5,7 @@ on: [push, pull_request]
 jobs:
 
   tests:
-    runs-on: self-hosted
+    runs-on: [self-hosted, macOS]
     if: github.repository == 'stfc/janus-core'
     timeout-minutes: 30
     strategy: