diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index e6ff926906..585c661a5c 100644
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -1546,26 +1546,22 @@ nsObjectLoadingContent::MaybeRewriteYoutubeEmbed(nsIURI* aURI, nsIURI* aBaseURI,
   }
 
   // See if requester is planning on using the JS API.
-  nsAutoCString uri;
-  nsresult rv = aURI->GetSpec(uri);
+  nsAutoCString prePath;
+  nsresult rv = aURI->GetPrePath(prePath);
   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);
+  int32_t ampIndex = path.FindChar('&', 0);
   bool replaceQuery = false;
   if (ampIndex != -1) {
-    int32_t qmIndex = uri.FindChar('?', 0);
+    int32_t qmIndex = path.FindChar('?', 0);
     if (qmIndex == -1 ||
         qmIndex > ampIndex) {
       replaceQuery = true;
@@ -1576,20 +1572,22 @@ nsObjectLoadingContent::MaybeRewriteYoutubeEmbed(nsIURI* aURI, nsIURI* aBaseURI,
     return;
   }
 
-  nsAutoString utf16OldURI = NS_ConvertUTF8toUTF16(uri);
+  NS_ConvertUTF8toUTF16 utf16OldURI(prePath);
+  AppendUTF8toUTF16(path, utf16OldURI);
   // If we need to convert the URL, it means an ampersand comes first.
   // Use the index we found earlier.
   if (replaceQuery) {
     // Replace question marks with ampersands.
-    uri.ReplaceChar('?', '&');
+    path.ReplaceChar('?', '&');
     // Replace the first ampersand with a question mark.
-    uri.SetCharAt('?', ampIndex);
+    path.SetCharAt('?', ampIndex);
   }
   // Switch out video access url formats, which should possibly allow HTML5
   // video loading.
-  uri.ReplaceSubstring(NS_LITERAL_CSTRING("/v/"),
-                       NS_LITERAL_CSTRING("/embed/"));
-  nsAutoString utf16URI = NS_ConvertUTF8toUTF16(uri);
+  path.ReplaceSubstring(NS_LITERAL_CSTRING("/v/"),
+                        NS_LITERAL_CSTRING("/embed/"));
+  NS_ConvertUTF8toUTF16 utf16URI(prePath);
+  AppendUTF8toUTF16(path, utf16URI);
   rv = nsContentUtils::NewURIWithDocumentCharset(aOutURI,
                                                  utf16URI,
                                                  thisContent->OwnerDoc(),
diff --git a/dom/base/nsObjectLoadingContent.h b/dom/base/nsObjectLoadingContent.h
index 24f80dd083..37bf83bad4 100644
--- a/dom/base/nsObjectLoadingContent.h
+++ b/dom/base/nsObjectLoadingContent.h
@@ -572,12 +572,12 @@ class nsObjectLoadingContent : public nsImageLoadingContent
      *
      * - 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