diff --git a/lib/Gitlab/HttpClient/Listener/ErrorListener.php b/lib/Gitlab/HttpClient/Listener/ErrorListener.php
index 4ec931cbb..cb2acc68b 100644
--- a/lib/Gitlab/HttpClient/Listener/ErrorListener.php
+++ b/lib/Gitlab/HttpClient/Listener/ErrorListener.php
@@ -50,7 +50,10 @@ public function postSend(RequestInterface $request, MessageInterface $response)
 
             $errorMessage = null;
             if (isset($content['error'])) {
-                $errorMessage = implode("\n", $content['error']);
+                $errorMessage = $content['error'];
+                if (is_array($content['error'])) {
+                    $errorMessage = implode("\n", $content['error']);
+                }
             } elseif (isset($content['message'])) {
                 $errorMessage = $this->parseMessage($content['message']);
             } else {