diff --git a/restclient.php b/restclient.php
index 3756d40..d98845c 100755
--- a/restclient.php
+++ b/restclient.php
@@ -243,8 +243,7 @@ public function parse_response($response) : void {
     
     public function get_response_format() : string {
         if(!$this->response)
-            throw new RestClientException(
-                "A response must exist before it can be decoded.");
+            throw new RestClientException($this->error);
         
         // User-defined format. 
         if(!empty($this->options['format']))