diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index b905afe3b6..1cf249c407 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -192,12 +192,11 @@ jobs:
 
   test-php-psr7-implementations:
     name: Test on PHP ${{ matrix.php-version }} (+ psr7-${{ matrix.psr-7-library }})
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
         php-version: ['7.2']
-        os: [ubuntu-latest]
         php-extensions: ['mbstring, iconv, mysqli, zip, bz2']
         psr-7-library: ['guzzlehttp/psr7', 'slim/psr7', 'nyholm/psr7']
         include: