diff --git a/consts/mime_types.go b/consts/mime_types.go
index f0c2d37d4..4566bd5e2 100644
--- a/consts/mime_types.go
+++ b/consts/mime_types.go
@@ -11,6 +11,7 @@ func init() {
 		".ogx":  "application/ogg",
 		".aac":  "audio/mp4",
 		".m4a":  "audio/mp4",
+		".m4b":  "audio/mp4",
 		".flac": "audio/flac",
 		".wav":  "audio/x-wav",
 		".wma":  "audio/x-ms-wma",