diff --git a/.github/workflows/phpunit-tests.yml b/.github/workflows/phpunit-tests.yml
index 921d4971e1..ae6abc3ce7 100644
--- a/.github/workflows/phpunit-tests.yml
+++ b/.github/workflows/phpunit-tests.yml
@@ -66,19 +66,19 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [ '5.6.20', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1' ]
+        php: [ '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1' ]
         os: [ ubuntu-latest ]
         memcached: [ false ]
         split_slow: [ false ]
         multisite: [ false, true ]
         include:
           # Additional "slow" jobs for PHP 5.6.
-          - php: '5.6.20'
+          - php: '5.6'
             os: ubuntu-latest
             memcached: false
             multisite: false
             split_slow: true
-          - php: '5.6.20'
+          - php: '5.6'
             os: ubuntu-latest
             memcached: false
             multisite: true