diff --git a/phpBB/phpbb/di/container_builder.php b/phpBB/phpbb/di/container_builder.php
index cca641403b..8279daba5d 100644
--- a/phpBB/phpbb/di/container_builder.php
+++ b/phpBB/phpbb/di/container_builder.php
@@ -116,6 +116,11 @@ class container_builder
 	 */
 	private $env_parameters = [];
 
+	/**
+	 * @var \phpbb\db\driver\driver_interface
+	 */
+	protected $dbal_connection = null;
+
 	/**
 	 * Constructor
 	 *
@@ -568,20 +573,22 @@ class container_builder
 		$config_data = $this->config_php_file->get_all();
 		if (!empty($config_data))
 		{
-			$dbal_driver_class = \phpbb\config_php_file::convert_30_dbms_to_31($this->config_php_file->get('dbms'));
-			/** @var \phpbb\db\driver\driver_interface $dbal_connection */
-			$dbal_connection = new $dbal_driver_class();
-			$dbal_connection->sql_connect(
-				$this->config_php_file->get('dbhost'),
-				$this->config_php_file->get('dbuser'),
-				$this->config_php_file->get('dbpasswd'),
-				$this->config_php_file->get('dbname'),
-				$this->config_php_file->get('dbport'),
-				false,
-				defined('PHPBB_DB_NEW_LINK') && PHPBB_DB_NEW_LINK
-			);
-			//$this->dbal_connection_doctrine = connection_factory::get_connection($this->config_php_file);
-			$this->container->set('dbal.conn.driver', $dbal_connection);
+			if ($this->dbal_connection === null)
+			{
+				$dbal_driver_class = \phpbb\config_php_file::convert_30_dbms_to_31($this->config_php_file->get('dbms'));
+				/** @var \phpbb\db\driver\driver_interface $dbal_connection */
+				$this->dbal_connection = new $dbal_driver_class();
+				$this->dbal_connection->sql_connect(
+					$this->config_php_file->get('dbhost'),
+					$this->config_php_file->get('dbuser'),
+					$this->config_php_file->get('dbpasswd'),
+					$this->config_php_file->get('dbname'),
+					$this->config_php_file->get('dbport'),
+					false,
+					defined('PHPBB_DB_NEW_LINK') && PHPBB_DB_NEW_LINK
+				);
+			}
+			$this->container->set('dbal.conn.driver', $this->dbal_connection);
 		}
 	}
 
diff --git a/tests/dbal/db_tools_test.php b/tests/dbal/db_tools_test.php
index f6344abdb2..70295b2165 100644
--- a/tests/dbal/db_tools_test.php
+++ b/tests/dbal/db_tools_test.php
@@ -360,7 +360,7 @@ class phpbb_dbal_db_tools_test extends phpbb_database_test_case
 	public function test_perform_schema_changes_drop_tables()
 	{
 		$db_tools = $this->getMockBuilder('\phpbb\db\tools\doctrine')
-			->onlyMethods(array('sql_table_exists', '_schema_drop_table'))
+			->onlyMethods(array('sql_table_exists', 'schema_drop_table'))
 			->setConstructorArgs(array($this->doctrine_db))
 			->getMock();
 
@@ -369,7 +369,7 @@ class phpbb_dbal_db_tools_test extends phpbb_database_test_case
 			->will($this->returnValue(true));
 
 		// drop tables
-		$db_tools->expects($this->exactly(2))->method('_schema_drop_table')
+		$db_tools->expects($this->exactly(2))->method('schema_drop_table')
 			->withConsecutive(
 				[$this->isInstanceOf(Schema::class), 'dropped_table_1', true],
 				[$this->isInstanceOf(Schema::class), 'dropped_table_2', true]