diff --git a/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp b/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

index 8929f2e..419330d 100644

--- a/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

+++ b/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

@@ -1767,7 +1767,7 @@ static HashSet<String> mimeTypeCache()

         "video/flv",

         "video/mj2",

         "video/mp2t",

-        "video/mp4",

+//        "video/mp4",

         "video/mpeg",

         "video/mpegts",

         "video/ogg",

@@ -1794,6 +1794,20 @@ static HashSet<String> mimeTypeCache()

     for (unsigned i = 0; i < (sizeof(mimeTypes) / sizeof(*mimeTypes)); ++i)

         cache.add(String(mimeTypes[i]));

+    // Hack to make YouTube work, https://bugs.webkit.org/show_bug.cgi?id=135972

+    gint exit_status = 1;

+    GUniqueOutPtr<GError> error;

+    GUniqueOutPtr<char> stdout_to_discard;

+    GUniqueOutPtr<char> stderr_to_discard;

+    gboolean success = g_spawn_command_line_sync(

+        "rpm -qi gstreamer1-libav",

+        &stdout_to_discard.outPtr(),

+        &stderr_to_discard.outPtr(),

+        &exit_status,

+        &error.outPtr());

+    if (success && !error && !exit_status)

+        cache.add(String::fromUTF8("video/mp4"));

+

     typeListInitialized = true;

     return cache;

 }