diff --git a/src/UploadImageBehavior.php b/src/UploadImageBehavior.php
index 4a9e48a..4baa6ac 100644
--- a/src/UploadImageBehavior.php
+++ b/src/UploadImageBehavior.php
@@ -133,7 +133,7 @@ protected function afterUpload()
     protected function createThumbs()
     {
         $path = $this->getUploadPath($this->attribute);
-        if (!is_file($path)) {
+        if (!is_string($path) || !is_file($path)) {
             return;
         }