diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b894b5d9..50ad379e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ on:
 jobs:
   tests:
     name: Tests PHP ${{ matrix.php }}, Symfony ${{ matrix.symfony }}, ${{ matrix.db }}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
 
     services:
       mysql: