diff --git a/.github/workflows/moodle-ci.yml b/.github/workflows/moodle-ci.yml
index 2f59ba0..8331a5a 100644
--- a/.github/workflows/moodle-ci.yml
+++ b/.github/workflows/moodle-ci.yml
@@ -8,7 +8,7 @@ jobs:
 
     services:
       postgres:
-        image: postgres:9.6
+        image: postgres:9.4
         env:
           POSTGRES_USER: 'postgres'
           POSTGRES_HOST_AUTH_METHOD: 'trust'
@@ -28,17 +28,17 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - php: '7.4'
-            moodle-branch: 'MOODLE_310_STABLE'
+          - php: '7.2'
+            moodle-branch: 'MOODLE_38_STABLE'
             database: pgsql
-          - php: '7.4'
-            moodle-branch: 'MOODLE_310_STABLE'
+          - php: '7.2'
+            moodle-branch: 'MOODLE_38_STABLE'
             database: mariadb
-          - php: '7.2'
-            moodle-branch: 'MOODLE_310_STABLE'
+          - php: '7.1'
+            moodle-branch: 'MOODLE_38_STABLE'
             database: pgsql
-          - php: '7.2'
-            moodle-branch: 'MOODLE_310_STABLE'
+          - php: '7.1'
+            moodle-branch: 'MOODLE_38_STABLE'
             database: mariadb
 
     steps: