diff --git a/dom/webidl/MozMobileConnection.webidl b/dom/webidl/MozMobileConnection.webidl
index d75b0a219e6..5c16958ad07 100644
--- a/dom/webidl/MozMobileConnection.webidl
+++ b/dom/webidl/MozMobileConnection.webidl
@@ -660,6 +660,11 @@ dictionary MozCallBarringOptions
 
 dictionary MozMMIResult
 {
+  /**
+   * Indicate whether the result is successful or not.
+   */
+  boolean success = true;
+
   /**
    * String key that identifies the service associated with the MMI code
    * request. The UI is supposed to handle the localization of the strings
@@ -668,7 +673,9 @@ dictionary MozMMIResult
   DOMString serviceCode = "";
 
   /**
-   * String key containing the status message of the associated MMI request.
+   * String key containing the status message of the associated MMI request or
+   * the error message when the request fails.
+
    * The UI is supposed to handle the localization of the strings associated
    * with this string key.
    */