diff --git a/src/MeshClient.php b/src/MeshClient.php
index 2c69db7..ad69231 100644
--- a/src/MeshClient.php
+++ b/src/MeshClient.php
@@ -171,7 +171,7 @@ protected function setMultipart(RequestInterface $request)
 
             foreach ($_FILES as $key => $value) {
                 // only add file part if a file was provided in the request
-                if (!empty($value['value'])) {
+                if (!empty($value['tmp_name'])) {
                     $tmp = array();
                     $tmp['name'] = $key;
                     $tmp['filename'] = $value['name'];