--- a/testing/marionette/event.js
+++ b/testing/marionette/event.js
@@ -1301,34 +1301,34 @@ event.focus = function(el, opts = {}) {
   let win = doc.defaultView;
 
   let ev = new win.FocusEvent(el);
   ev.initEvent("focus", opts.canBubble, true);
   el.dispatchEvent(ev);
 };
 
 event.mouseover = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "mouseover"}, el, modifiers, opts);
+  return event.sendEvent("mouseover", el, modifiers, opts);
 };
 
 event.mousemove = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "mousemove"}, el, modifiers, opts);
+  return event.sendEvent("mousemove", el, modifiers, opts);
 };
 
 event.mousedown = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "mousedown"}, el, modifiers, opts);
+  return event.sendEvent("mousedown", el, modifiers, opts);
 };
 
 event.mouseup = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "mouseup"}, el, modifiers, opts);
+  return event.sendEvent("mouseup", el, modifiers, opts);
 };
 
 event.click = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "click"}, el, modifiers, opts);
+  return event.sendEvent("click", el, modifiers, opts);
 };
 
 event.change = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "change"}, el, modifiers, opts);
+  return event.sendEvent("change", el, modifiers, opts);
 };
 
 event.input = function(el, modifiers = {}, opts = {}) {
-  return event.sendEvent({type: "input"}, el, modifiers, opts);
+  return event.sendEvent("input", el, modifiers, opts);
 };