diff --git a/src/response/AuthResponse.js b/src/response/AuthResponse.js
index 5a4abee5..81c90c49 100644
--- a/src/response/AuthResponse.js
+++ b/src/response/AuthResponse.js
@@ -144,7 +144,7 @@ AuthResponse.prototype.getContentType = function getContentType() {
  * @returns {boolean} isJson
  */
 AuthResponse.prototype.isJson = function isJson() {
-  return this.isContentType('application/json');
+  return this.isContentType(AuthResponse._jsonContentType);
 };