--- a/media-plugins/gst-plugins-meta/metadata.xml	
+++ a/media-plugins/gst-plugins-meta/metadata.xml	
@@ -12,10 +12,11 @@ since gstreamer plugins are all run-time dependencies.
 <use>
 	<flag name='http'>Enable http streaming via <pkg>net-libs/libsoup</pkg></flag>
 	<flag name='opus'>Enable Opus audio codec support</flag>
-	<flag name='libvisual'>Enable visualization effects via 
+	<flag name='libvisual'>Enable visualization effects via
 		<pkg>media-libs/libvisual</pkg></flag>
 	<flag name='vpx'>Enables vp8 codec support using libvpx, required to
 		play some HTML5 videos</flag>
+	<flag name="mpg123">Enable mp3 decoding support via <pkg>media-sound/mpg123</pkg>
+		instead of <pkg>media-libs/libmad</pkg></flag>
 </use>
 </pkgmetadata>
-