diff --git a/app/Http/Controllers/PublicController.php b/app/Http/Controllers/PublicController.php
index cdb60d7..bd1b4c8 100644
--- a/app/Http/Controllers/PublicController.php
+++ b/app/Http/Controllers/PublicController.php
@@ -44,7 +44,7 @@ class PublicController extends BaseController
 
     public function returnImageFile($tenant, $gallery, $image, Request $request) {
         $sizeName = $request->input("size", "medium");
-        if(array_key_exists($sizeName, $this->size)) {
+        if(!array_key_exists($sizeName, $this->size)) {
             abort(400, "Size not exists");
         }
         $size = $this->size[$sizeName];