diff --git a/CHANGELOG.md b/CHANGELOG.md
index 27a26d0117..dfeb38ae69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ All notable changes to this project will be documented in this file. This projec
 
 + [#129](https://github.com/luyadev/luya-module-admin/issues/129) Fixed problem when ngrest plugin try to write in object property instead of active record attribute.
 + [#125](https://github.com/luyadev/luya-module-admin/issues/125) Detach cruft behavior for global search response.
++ [#132](https://github.com/luyadev/luya-module-admin/pull/132) Fixed validation error on single file upload with the StorageUploadValidator.
 
 ## 1.2.0 (17. May 2018)
 
diff --git a/src/ngrest/validators/StorageUploadValidator.php b/src/ngrest/validators/StorageUploadValidator.php
index 20acd8d183..10aca8b87c 100644
--- a/src/ngrest/validators/StorageUploadValidator.php
+++ b/src/ngrest/validators/StorageUploadValidator.php
@@ -86,14 +86,18 @@ public function validateAttribute($model, $attribute)
             return;
         }
         
-        $files = $this->multiple ? UploadedFile::getInstances($model, $attribute) : (array) UploadedFile::getInstance($model, $attribute);
-        
+        $files = $this->multiple ? UploadedFile::getInstances($model, $attribute) : UploadedFile::getInstance($model, $attribute);
+
         $contextModel = new DynamicModel(['file' => $files]);
         $contextModel->addRule(['file'], 'file', ['maxFiles' => $this->multiple ? 0 : 1])->validate();
-        
+
         if ($contextModel->hasErrors()) {
             return $this->addError($model, $attribute, $contextModel->getFirstError('file'));
         }
+
+        if (!is_array($files)) {
+            $files = [$files];
+        }
          
         $data = [];
         foreach ($files as $file) {