diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index b444f5123..1742f1696 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -66,7 +66,8 @@ jobs:
         run: cmake --build build --target ${{ matrix.target }}
 
   ci_cmake_flags:
-    runs-on: ubuntu-focal
+    runs-on: ubuntu-latest
+    container: ubuntu:focal
     steps:
       - uses: actions/checkout@v3
       - name: Get latest CMake and ninja