diff --git a/system/src/Grav/Common/Page/Medium/ImageFile.php b/system/src/Grav/Common/Page/Medium/ImageFile.php
index 2aa308ff7..c71cd0efd 100644
--- a/system/src/Grav/Common/Page/Medium/ImageFile.php
+++ b/system/src/Grav/Common/Page/Medium/ImageFile.php
@@ -80,7 +80,8 @@ class ImageFile extends Image
 
         // Asking the cache for the cacheFile
         try {
-            $perms = (string)self::getGrav()['config']->get('system.images.cache_perms', '0755');
+            $perms = self::getGrav()['config']->get('system.images.cache_perms', '0755');
+            $perms = octdec($perms);
             $file = $this->cache->setDirectoryMode($perms)->getOrCreateFile($cacheFile, $conditions, $generate, $actual);
         } catch (GenerationError $e) {
             $file = $e->getNewFile();