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;
 }