diff --git a/phpBB/phpbb/db/driver/driver.php b/phpBB/phpbb/db/driver/driver.php
index 61a2044040..52e8545f36 100644
--- a/phpBB/phpbb/db/driver/driver.php
+++ b/phpBB/phpbb/db/driver/driver.php
@@ -1330,7 +1330,7 @@ abstract class driver implements driver_interface
 	/**
 	 * {@inheritDoc}
 	 */
-	public function clean_query_id(mixed $query_id): int|string
+	public function clean_query_id(mixed $query_id): int|string|null
 	{
 		// Some DBMS functions accept/return objects and/or resources instead if identifiers
 		// Attempting to use objects/resources as array keys will throw error, hence correctly handle all cases
diff --git a/phpBB/phpbb/db/driver/driver_interface.php b/phpBB/phpbb/db/driver/driver_interface.php
index 0f90f5fdeb..918add2e62 100644
--- a/phpBB/phpbb/db/driver/driver_interface.php
+++ b/phpBB/phpbb/db/driver/driver_interface.php
@@ -501,7 +501,7 @@ interface driver_interface
 	 *
 	 * @param mixed $query_id Mixed type query id
 	 *
-	 * @return int|string Query id in string or integer format
+	 * @return int|string|null Query id in string or integer format
 	 */
-	public function clean_query_id(mixed $query_id): int|string;
+	public function clean_query_id(mixed $query_id): int|string|null;
 }
diff --git a/phpBB/phpbb/db/driver/factory.php b/phpBB/phpbb/db/driver/factory.php
index 4aaf52902d..4d28ab1032 100644
--- a/phpBB/phpbb/db/driver/factory.php
+++ b/phpBB/phpbb/db/driver/factory.php
@@ -478,7 +478,7 @@ class factory implements driver_interface
 	/**
 	 * {@inheritDoc}
 	 */
-	public function clean_query_id(mixed $query_id): int|string
+	public function clean_query_id(mixed $query_id): int|string|null
 	{
 		return $this->get_driver()->clean_query_id($query_id);
 	}
diff --git a/phpBB/phpbb/db/driver/postgres.php b/phpBB/phpbb/db/driver/postgres.php
index 31137634fe..1f695acb83 100644
--- a/phpBB/phpbb/db/driver/postgres.php
+++ b/phpBB/phpbb/db/driver/postgres.php
@@ -436,7 +436,7 @@ class postgres extends \phpbb\db\driver\driver
 		{
 			return true;
 		}
-		return @pg_close($this->db_connect_id);
+		return pg_close($this->db_connect_id);
 	}
 
 	/**
diff --git a/tests/test_framework/phpbb_database_test_case.php b/tests/test_framework/phpbb_database_test_case.php
index e8d5a653a6..0c0317fe10 100644
--- a/tests/test_framework/phpbb_database_test_case.php
+++ b/tests/test_framework/phpbb_database_test_case.php
@@ -303,8 +303,9 @@ abstract class phpbb_database_test_case extends TestCase
 	{
 		$config = $this->get_database_config();
 
+		/** @var \phpbb\db\driver\driver_interface $db */
 		$db = new $config['dbms']();
-		$db->sql_connect($config['dbhost'], $config['dbuser'], $config['dbpasswd'], $config['dbname'], $config['dbport']);
+		$db->sql_connect($config['dbhost'], $config['dbuser'], $config['dbpasswd'], $config['dbname'], $config['dbport'], false, true);
 
 		$this->db_connections[] = $db;