diff --git a/netwerk/mime/nsMimeTypes.h b/netwerk/mime/nsMimeTypes.h
index 7434db383c..aba444de2f 100644
--- a/netwerk/mime/nsMimeTypes.h
+++ b/netwerk/mime/nsMimeTypes.h
@@ -88,7 +88,6 @@
 #define AUDIO_3GPP2                         "audio/3gpp2"
 #define AUDIO_MIDI                          "audio/x-midi"
 #define AUDIO_MATROSKA                      "audio/x-matroska"
-#define AUDIO_FLAC                          "audio/flac"
 
 #define BINARY_OCTET_STREAM                 "binary/octet-stream"