diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index 9385d5bb..2cab0aa0 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -9,7 +9,7 @@ on:
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-16.04
 
     steps:
     - uses: actions/checkout@v2