diff --git a/src/Subscriber/ListRepository.php b/src/Subscriber/ListRepository.php
index eff3b59..f092ac4 100644
--- a/src/Subscriber/ListRepository.php
+++ b/src/Subscriber/ListRepository.php
@@ -514,7 +514,7 @@ public function getWebhooks($listId)
     private function throwMailchimpError(array $errorResponse)
     {
         $errorArray = json_decode($errorResponse['body'], true);
-        if (array_key_exists('errors', $errorArray)) {
+        if (is_array($errorArray) && array_key_exists('errors', $errorArray)) {
             throw new MailchimpException(
                 $errorArray['status'],
                 $errorArray['detail'],