diff --git a/components/script/dom/event.rs b/components/script/dom/event.rs
index 637bd259035..6d7ce64bf5e 100644
--- a/components/script/dom/event.rs
+++ b/components/script/dom/event.rs
@@ -245,3 +245,13 @@ impl Reflectable for Event {
         &self.reflector_
     }
 }
+
+pub trait EventHelpers {
+    fn set_trusted(self, trusted: bool);
+}
+
+impl<'a> EventHelpers for JSRef<'a, Event> {
+    fn set_trusted(self, trusted: bool) {
+        self.trusted.set(trusted);
+    }
+}
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index 3ac799fdc04..1d12bdebf39 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -15,7 +15,7 @@ use dom::bindings::utils::{Reflectable, Reflector};
 use dom::document::{Document, DocumentHelpers};
 use dom::element::{Element, AttributeHandlers, HTMLFormElementTypeId, HTMLTextAreaElementTypeId, HTMLDataListElementTypeId};
 use dom::element::{HTMLInputElementTypeId, HTMLButtonElementTypeId, HTMLObjectElementTypeId, HTMLSelectElementTypeId};
-use dom::event::{Event, Bubbles, Cancelable};
+use dom::event::{Event, EventHelpers, Bubbles, Cancelable};
 use dom::eventtarget::{EventTarget, NodeTargetTypeId};
 use dom::htmlelement::HTMLElement;
 use dom::htmlinputelement::HTMLInputElement;
@@ -142,6 +142,7 @@ impl<'a> HTMLFormElementHelpers for JSRef<'a, HTMLFormElement> {
         let event = Event::new(Window(*win),
                                "submit".to_string(),
                                Bubbles, Cancelable).root();
+        event.set_trusted(true);
         let target: JSRef<EventTarget> = EventTargetCast::from_ref(self);
         target.DispatchEvent(*event).ok();
         if event.DefaultPrevented() {