diff --git a/uriloader/exthandler/nsExternalHelperAppService.cpp b/uriloader/exthandler/nsExternalHelperAppService.cpp
index 7393c3941..d57934ac9 100644
--- a/uriloader/exthandler/nsExternalHelperAppService.cpp
+++ b/uriloader/exthandler/nsExternalHelperAppService.cpp
@@ -475,6 +475,7 @@ static const nsDefaultMimeTypeEntry defaultMimeEntries[] =
   { APPLICATION_PDF, "pdf" },
   { VIDEO_WEBM, "webm" },
   { AUDIO_WEBM, "webm" },
+  { AUDIO_FLAC, "flac" },
 #if defined(MOZ_WMF)
   { VIDEO_MP4, "mp4" },
   { AUDIO_MP4, "m4a" },