diff --git a/install/core/actions/setupConfirmation.php b/install/core/actions/setupConfirmation.php
index b0eeabece2..a0dbccef74 100644
--- a/install/core/actions/setupConfirmation.php
+++ b/install/core/actions/setupConfirmation.php
@@ -39,7 +39,7 @@ $dbConfig = [
     'dbname' => $installData['db-name'],
     'user' => $installData['db-user-name'],
     'password' => $installData['db-user-password'],
-    'platform' => $installData['db-platform']
+    'platform' => $installData['db-platform'] ?? null,
 ];
 
 $mysqlRequirementList = $installer->getSystemRequirementList('database', false, ['databaseParams' => $dbConfig]);