diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b0777be..e624585 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,13 +13,13 @@ jobs:
             database: 'pgsql'
           - php: '8.0'
             moodle-branch: 'MOODLE_403_STABLE'
-            database: 'pgsql'
+            database: 'mariadb'
           - php: '8.1'
             moodle-branch: 'MOODLE_402_STABLE'
             database: 'pgsql'
           - php: '8.0'
             moodle-branch: 'MOODLE_401_STABLE'
-            database: 'pgsql'
+            database: 'mariadb'
 
     services:
       postgres:
diff --git a/tests/behat/behat_report_customsql.php b/tests/behat/behat_report_customsql.php
index 5d491cc..56b124a 100644
--- a/tests/behat/behat_report_customsql.php
+++ b/tests/behat/behat_report_customsql.php
@@ -78,6 +78,11 @@ public function the_following_custom_sql_report_exists(TableNode $data) {
             throw new Exception('The report SQL must be given as querysql.');
         }
 
+        // Fix test queries containing CHR for MySQL & chums.
+        if ($DB->get_dbfamily() == 'mysql' && stripos($report['querysql'], 'CHR') !== false) {
+            $report['querysql'] = str_ireplace('CHR', 'CHAR', $report['querysql']);
+        }
+
         // Category.
         if (isset($report['category'])) {
             $report['categoryid'] = $this->get_category_id_by_name($report['category']);