diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 49981e36..7d6a9975 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,5 +12,6 @@ concurrency:
 
 jobs:
   puppet:
+    runs-on: ubuntu-20.04
     name: Puppet
     uses: voxpupuli/gha-puppet/.github/workflows/basic.yml@v1