diff --git a/phpBB/install/startup.php b/phpBB/install/startup.php
index 0aaa9a648f..0180996a19 100644
--- a/phpBB/install/startup.php
+++ b/phpBB/install/startup.php
@@ -161,7 +161,7 @@ function installer_shutdown_function($display_errors)
 
 		$cache = new \phpbb\cache\driver\file(__DIR__ . '/../cache/installer');
 		$filesystem = new \phpbb\filesystem\filesystem();
-		if (strpos($error['file'], $filesystem->realpath($cache->cache_dir)) !== false)
+		if (strpos($error['file'], $filesystem->realpath($cache->cache_dir)) !== false && is_writable($cache->cache_dir))
 		{
 			$file_age = @filemtime($error['file']);
 
diff --git a/phpBB/phpbb/cache/driver/file.php b/phpBB/phpbb/cache/driver/file.php
index 36150d0589..4190f65342 100644
--- a/phpBB/phpbb/cache/driver/file.php
+++ b/phpBB/phpbb/cache/driver/file.php
@@ -37,9 +37,9 @@ 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 (!is_dir($this->cache_dir))
+		if ($this->filesystem->is_writable($this->cache_dir . '/../') && !is_dir($this->cache_dir))
 		{
-			@mkdir($this->cache_dir, 0777, true);
+			mkdir($this->cache_dir, 0777, true);
 		}
 	}
 
diff --git a/phpBB/phpbb/filesystem/filesystem.php b/phpBB/phpbb/filesystem/filesystem.php
index fc7cbdf27d..3e60a6f2fb 100644
--- a/phpBB/phpbb/filesystem/filesystem.php
+++ b/phpBB/phpbb/filesystem/filesystem.php
@@ -398,13 +398,13 @@ class filesystem implements filesystem_interface
 					$file_gid = @filegroup($file);
 
 					// Change owner
-					if ($file_uid !== $this->chmod_info['common_owner'])
+					if (is_writable($file) && $file_uid !== $this->chmod_info['common_owner'])
 					{
 						$this->chown($file, $this->chmod_info['common_owner'], $recursive);
 					}
 
 					// Change group
-					if ($file_gid !== $this->chmod_info['common_group'])
+					if (is_writable($file) && $file_gid !== $this->chmod_info['common_group'])
 					{
 						$this->chgrp($file, $this->chmod_info['common_group'], $recursive);
 					}