diff --git a/phpBB/phpbb/config_php_file.php b/phpBB/phpbb/config_php_file.php
index 09017ad47a..be17906ad1 100644
--- a/phpBB/phpbb/config_php_file.php
+++ b/phpBB/phpbb/config_php_file.php
@@ -100,6 +100,7 @@ class config_php_file
 	{
 		if (!$this->config_loaded && file_exists($this->config_file))
 		{
+			$defined_vars = null; // Define variable before call get_defined_vars
 			$defined_vars = get_defined_vars();
 
 			require($this->config_file);
diff --git a/tests/migrations/migrations_check_config_added_test.php b/tests/migrations/migrations_check_config_added_test.php
index 9c34428dae..cf3f8e9ea0 100644
--- a/tests/migrations/migrations_check_config_added_test.php
+++ b/tests/migrations/migrations_check_config_added_test.php
@@ -48,6 +48,7 @@ class migrations_check_config_added_test extends phpbb_test_case
 			$this->php_ext,
 			$this->table_prefix,
 			[],
+			[],
 			new \phpbb\db\migration\helper()
 		);
 		$this->container->set('migrator', $this->migrator);