--- a/dom/html/nsBrowserElement.cpp
+++ b/dom/html/nsBrowserElement.cpp
@@ -260,18 +260,19 @@ nsBrowserElement::Download(const nsAStri
 
   nsCOMPtr<nsIDOMDOMRequest> req;
   nsCOMPtr<nsIXPConnectWrappedJS> wrappedObj = do_QueryInterface(mBrowserElementAPI);
   MOZ_ASSERT(wrappedObj, "Failed to get wrapped JS from XPCOM component.");
   AutoJSAPI jsapi;
   jsapi.Init(wrappedObj->GetJSObject());
   JSContext* cx = jsapi.cx();
   JS::Rooted<JS::Value> options(cx);
+  aRv.MightThrowJSException();
   if (!ToJSValue(cx, aOptions, &options)) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    aRv.StealExceptionFromJSContext(cx);
     return nullptr;
   }
   nsresult rv = mBrowserElementAPI->Download(aUrl, options, getter_AddRefs(req));
 
   if (NS_WARN_IF(NS_FAILED(rv))) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return nullptr;
   }
@@ -759,18 +760,19 @@ nsBrowserElement::ExecuteScript(const ns
 
   nsCOMPtr<nsIDOMDOMRequest> req;
   nsCOMPtr<nsIXPConnectWrappedJS> wrappedObj = do_QueryInterface(mBrowserElementAPI);
   MOZ_ASSERT(wrappedObj, "Failed to get wrapped JS from XPCOM component.");
   AutoJSAPI jsapi;
   jsapi.Init(wrappedObj->GetJSObject());
   JSContext* cx = jsapi.cx();
   JS::Rooted<JS::Value> options(cx);
+  aRv.MightThrowJSException();
   if (!ToJSValue(cx, aOptions, &options)) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    aRv.StealExceptionFromJSContext(cx);
     return nullptr;
   }
 
   nsresult rv = mBrowserElementAPI->ExecuteScript(aScript, options, getter_AddRefs(req));
 
   if (NS_FAILED(rv)) {
     if (rv == NS_ERROR_INVALID_ARG) {
       aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);