diff --git a/phpBB/includes/di/extension/config.php b/phpBB/includes/di/extension/config.php
index 85ab7ab28d..97a6290066 100644
--- a/phpBB/includes/di/extension/config.php
+++ b/phpBB/includes/di/extension/config.php
@@ -44,7 +44,7 @@ class phpbb_di_extension_config extends Extension
 
 		$container->setParameter('core.table_prefix', $table_prefix);
 		$container->setParameter('cache.driver.class', $this->convert_30_acm_type($acm_type));
-		$container->setParameter('dbal.driver.class', $this->convert_30_dbms($dbms));
+		$container->setParameter('dbal.driver.class', phpbb_convert_30_dbms_to_31($dbms));
 		$container->setParameter('dbal.dbhost', $dbhost);
 		$container->setParameter('dbal.dbuser', $dbuser);
 		$container->setParameter('dbal.dbpasswd', $dbpasswd);
@@ -80,20 +80,4 @@ class phpbb_di_extension_config extends Extension
 
 		return $acm_type;
 	}
-
-	/**
-	* Convert 3.0 dbms to 3.1 db driver class name
-	*
-	* @param string $dbms dbms parameter
-	* @return db driver class
-	*/
-	protected function convert_30_dbms($dbms)
-	{
-		if (!preg_match('#^phpbb_db_driver_#', $dbms))
-		{
-			return 'phpbb_db_driver_'.$dbms;
-		}
-
-		return $dbms;
-	}
 }
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 804d89d1a2..045a28672b 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -5412,3 +5412,19 @@ function phpbb_to_numeric($input)
 {
 	return ($input > PHP_INT_MAX) ? (float) $input : (int) $input;
 }
+
+/**
+* Convert 3.0 dbms to 3.1 db driver class name
+*
+* @param string $dbms dbms parameter
+* @return db driver class
+*/
+function phpbb_convert_30_dbms_to_31($dbms)
+{
+	if (!preg_match('#^phpbb_db_driver_#', $dbms))
+	{
+		return 'phpbb_db_driver_'.$dbms;
+	}
+
+	return $dbms;
+}
diff --git a/phpBB/includes/questionnaire/questionnaire.php b/phpBB/includes/questionnaire/questionnaire.php
index f0fb8c3c06..6bbedacbe2 100644
--- a/phpBB/includes/questionnaire/questionnaire.php
+++ b/phpBB/includes/questionnaire/questionnaire.php
@@ -260,6 +260,8 @@ class phpbb_questionnaire_phpbb_data_provider
 		include("{$phpbb_root_path}config.$phpEx");
 		unset($dbhost, $dbport, $dbname, $dbuser, $dbpasswd); // Just a precaution
 
+		$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 		// Only send certain config vars
 		$config_vars = array(
 			'active_sessions' => true,
diff --git a/phpBB/install/convertors/convert_phpbb20.php b/phpBB/install/convertors/convert_phpbb20.php
index 68acea02b3..5f30625980 100644
--- a/phpBB/install/convertors/convert_phpbb20.php
+++ b/phpBB/install/convertors/convert_phpbb20.php
@@ -24,6 +24,8 @@ if (!defined('IN_PHPBB'))
 include($phpbb_root_path . 'config.' . $phpEx);
 unset($dbpasswd);
 
+$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 /**
 * $convertor_data provides some basic information about this convertor which is
 * used on the initial list of convertors and to populate the default settings
diff --git a/phpBB/install/install_convert.php b/phpBB/install/install_convert.php
index 48624dc2b8..9afe341ffa 100644
--- a/phpBB/install/install_convert.php
+++ b/phpBB/install/install_convert.php
@@ -123,6 +123,8 @@ class install_convert extends module
 				require($phpbb_root_path . 'includes/constants.' . $phpEx);
 				require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);
 
+				$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 				$db = new $dbms();
 				$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);
 				unset($dbpasswd);
@@ -210,6 +212,8 @@ class install_convert extends module
 				require($phpbb_root_path . 'includes/constants.' . $phpEx);
 				require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);
 
+				$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 				$db = new $dbms();
 				$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);
 				unset($dbpasswd);
@@ -332,6 +336,8 @@ class install_convert extends module
 		require($phpbb_root_path . 'includes/constants.' . $phpEx);
 		require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);
 
+		$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 		$db = new $dbms();
 		$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);
 		unset($dbpasswd);
@@ -573,6 +579,8 @@ class install_convert extends module
 		require($phpbb_root_path . 'includes/constants.' . $phpEx);
 		require($phpbb_root_path . 'includes/functions_convert.' . $phpEx);
 
+		$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 		$db = new $dbms();
 		$db->sql_connect($dbhost, $dbuser, $dbpasswd, $dbname, $dbport, false, true);
 		unset($dbpasswd);
diff --git a/phpBB/install/install_update.php b/phpBB/install/install_update.php
index 7d0d627e9d..a556056382 100644
--- a/phpBB/install/install_update.php
+++ b/phpBB/install/install_update.php
@@ -91,6 +91,8 @@ class install_update extends module
 		define('MERGE_NEW_FILE', 3);
 		define('MERGE_MOD_FILE', 4);
 
+		$dbms = phpbb_convert_30_dbms_to_31($dbms);
+
 		$db = new $dbms();
 
 		// Connect to DB
diff --git a/tests/test_framework/phpbb_test_case_helpers.php b/tests/test_framework/phpbb_test_case_helpers.php
index 9bbdcff440..96a546e538 100644
--- a/tests/test_framework/phpbb_test_case_helpers.php
+++ b/tests/test_framework/phpbb_test_case_helpers.php
@@ -78,7 +78,7 @@ class phpbb_test_case_helpers
 			include($test_config);
 
 			$config = array_merge($config, array(
-				'dbms'		=> $this->convert_30_dbms($dbms),
+				'dbms'		=> phpbb_convert_30_dbms_to_31($dbms),
 				'dbhost'	=> $dbhost,
 				'dbport'	=> $dbport,
 				'dbname'	=> $dbname,
@@ -96,7 +96,7 @@ class phpbb_test_case_helpers
 		if (isset($_SERVER['PHPBB_TEST_DBMS']))
 		{
 			$config = array_merge($config, array(
-				'dbms'		=> isset($_SERVER['PHPBB_TEST_DBMS']) ? $this->convert_30_dbms($_SERVER['PHPBB_TEST_DBMS']) : '',
+				'dbms'		=> isset($_SERVER['PHPBB_TEST_DBMS']) ? phpbb_convert_30_dbms_to_31($_SERVER['PHPBB_TEST_DBMS']) : '',
 				'dbhost'	=> isset($_SERVER['PHPBB_TEST_DBHOST']) ? $_SERVER['PHPBB_TEST_DBHOST'] : '',
 				'dbport'	=> isset($_SERVER['PHPBB_TEST_DBPORT']) ? $_SERVER['PHPBB_TEST_DBPORT'] : '',
 				'dbname'	=> isset($_SERVER['PHPBB_TEST_DBNAME']) ? $_SERVER['PHPBB_TEST_DBNAME'] : '',
@@ -223,20 +223,4 @@ class phpbb_test_case_helpers
 			}
 		}
 	}
-
-	/**
-	* Convert 3.0 dbms to 3.1 db driver class name
-	*
-	* @param string $dbms dbms parameter
-	* @return db driver class
-	*/
-	protected function convert_30_dbms($dbms)
-	{
-		if (!preg_match('#^phpbb_db_driver_#', $dbms))
-		{
-			return 'phpbb_db_driver_'.$dbms;
-		}
-
-		return $dbms;
-	}
 }