--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -1399,20 +1399,16 @@ nsObjectLoadingContent::MaybeRewriteYout
 
   // See if requester is planning on using the JS API.
   nsAutoCString uri;
   nsresult rv = aURI->GetSpec(uri);
   if (NS_FAILED(rv)) {
     return;
   }
 
-  if (uri.Find("enablejsapi=1", true, 0, -1) != kNotFound) {
-    return;
-  }
-
   // Some YouTube urls have parameters in path components, e.g.
   // http://youtube.com/embed/7LcUOEP7Brc&start=35. These URLs work with flash,
   // but break iframe/object embedding. If this situation occurs with rewritten
   // URLs, convert the parameters to query in order to make the video load
   // correctly as an iframe. In either case, warn about it in the
   // developer console.
   int32_t ampIndex = uri.FindChar('&', 0);
   bool replaceQuery = false;

--- a/dom/base/nsObjectLoadingContent.h
+++ b/dom/base/nsObjectLoadingContent.h
@@ -577,22 +577,22 @@ class nsObjectLoadingContent : public ns
      * Used for identifying whether we can rewrite a youtube flash embed to
      * possibly use HTML5 instead.
      *
      * Returns true if plugin.rewrite_youtube_embeds pref is true and the
      * element this nsObjectLoadingContent instance represents:
      *
      * - is an embed or object node
      * - has a URL pointing at the youtube.com domain, using "/v/" style video
-     *   path reference, and without enablejsapi=1 in the path
+     *   path reference.
      *
      * Having the enablejsapi flag means the document that contains the element
      * could possibly be manipulating the youtube video elsewhere on the page
-     * via javascript. We can't rewrite these kinds of elements without possibly
-     * breaking content, which we want to avoid.
+     * via javascript. In the context of embed elements, this usage has been
+     * deprecated by youtube, so we can just rewrite as normal.
      *
      * If we can rewrite the URL, we change the "/v/" to "/embed/", and change
      * our type to eType_Document so that we render similarly to an iframe
      * embed.
      */
     void MaybeRewriteYoutubeEmbed(nsIURI* aURI,
                                   nsIURI* aBaseURI,
                                   nsIURI** aRewrittenURI);