new file mode 100644
--- /dev/null
+++ b/dom/webidl/MediaRecorderErrorEvent.webidl
@@ -0,0 +1,21 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * https://w3c.github.io/mediacapture-record/
+ *
+ * Copyright © 2017 W3C® (MIT, ERCIM, Keio, Beihang). W3C liability, trademark
+ * and document use rules apply.
+ */
+
+dictionary MediaRecorderErrorEventInit : EventInit {
+  required DOMException error;
+};
+
+[Exposed=Window,
+  Constructor(DOMString type, MediaRecorderErrorEventInit eventInitDict)]
+interface MediaRecorderErrorEvent : Event {
+  [SameObject] readonly attribute DOMException error;
+};
\ No newline at end of file

--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -1075,16 +1075,17 @@ GENERATED_EVENTS_WEBIDL_FILES = [
     'GamepadAxisMoveEvent.webidl',
     'GamepadButtonEvent.webidl',
     'GamepadEvent.webidl',
     'GroupedHistoryEvent.webidl',
     'HashChangeEvent.webidl',
     'HiddenPluginEvent.webidl',
     'ImageCaptureErrorEvent.webidl',
     'MediaQueryListEvent.webidl',
+    'MediaRecorderErrorEvent.webidl',
     'MediaStreamEvent.webidl',
     'MediaStreamTrackEvent.webidl',
     'OfflineAudioCompletionEvent.webidl',
     'PageTransitionEvent.webidl',
     'PerformanceEntryEvent.webidl',
     'PluginCrashedEvent.webidl',
     'PopStateEvent.webidl',
     'PopupBlockedEvent.webidl',