diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e3a622d..dc74faf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,7 +35,7 @@
             exit 1
           fi
   formatting:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
       - name: Install Uncrustify