--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -314,17 +314,17 @@ pref("media.cache_readahead_limit", 30);
 // Enable/Disable Gonk Decoder Module
 pref("media.fragmented-mp4.gonk.enabled", true);
 #endif
 // The default number of decoded video frames that are enqueued in
 // MediaDecoderReader's mVideoQueue.
 pref("media.video-queue.default-size", 3);
 
 // optimize images' memory usage
-pref("image.mem.decodeondraw", false);
+pref("image.mem.decodeondraw", true);
 pref("image.mem.allow_locking_in_content_processes", false); /* don't allow image locking */
 // Limit the surface cache to 1/8 of main memory or 128MB, whichever is smaller.
 // Almost everything that was factored into 'max_decoded_image_kb' is now stored
 // in the surface cache.  1/8 of main memory is 32MB on a 256MB device, which is
 // about the same as the old 'max_decoded_image_kb'.
 pref("image.mem.surfacecache.max_size_kb", 131072);  // 128MB
 pref("image.mem.surfacecache.size_factor", 8);  // 1/8 of main memory
 pref("image.mem.surfacecache.discard_factor", 2);  // Discard 1/2 of the surface cache at a time.