diff --git a/phpBB/includes/acp/acp_main.php b/phpBB/includes/acp/acp_main.php
index bd50ea2046..77862e3b46 100644
--- a/phpBB/includes/acp/acp_main.php
+++ b/phpBB/includes/acp/acp_main.php
@@ -681,9 +681,9 @@ class acp_main
 
 		if (!defined('PHPBB_DISABLE_CONFIG_CHECK'))
 		{
-			$template->assign_var('S_WRITABLE_CONFIG',
-				(bool) $phpbb_filesystem->is_writable($phpbb_root_path . 'config.' . $phpEx) || (@fileperms($phpbb_root_path . 'config.' . $phpEx) & 0x0002)
-			);
+			$phpbb_config_file = $phpbb_root_path . 'config.' . $phpEx;
+
+			$template->assign_var('S_WRITABLE_CONFIG', (bool) $phpbb_filesystem->is_writable($phpbb_config_file) || (@fileperms($phpbb_config_file) & 0x0002));
 		}
 
 		$this->php_ini			= $phpbb_container->get('php_ini');