diff --git a/phpBB/phpbb/cache/driver/file.php b/phpBB/phpbb/cache/driver/file.php
index 4190f65342..a07b9a9701 100644
--- a/phpBB/phpbb/cache/driver/file.php
+++ b/phpBB/phpbb/cache/driver/file.php
@@ -37,7 +37,7 @@ class file extends \phpbb\cache\driver\base
 		$this->cache_dir = !is_null($cache_dir) ? $cache_dir : $phpbb_container->getParameter('core.cache_dir');
 		$this->filesystem = new \phpbb\filesystem\filesystem();
 
-		if ($this->filesystem->is_writable($this->cache_dir . '/../') && !is_dir($this->cache_dir))
+		if ($this->filesystem->is_writable(dirname($this->cache_dir)) && !is_dir($this->cache_dir))
 		{
 			mkdir($this->cache_dir, 0777, true);
 		}