diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7a1be1b..91f3fdf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
     container: ${{ matrix.image }}
     name: Build ${{ matrix.image }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: ${{ matrix.image == 'ubuntu:18.04' && 'actions/checkout@v3' || 'actions/checkout@v4' }}
     - name: Install dependencies
       run: |
         apt-get -qq update -y