diff --git a/types/audio.yaml b/types/audio.yaml
index 40bbab4..3975186 100644
--- a/types/audio.yaml
+++ b/types/audio.yaml
@@ -732,6 +732,11 @@
     template:
     - audio/mp4
   registered: true
+- !ruby/object:MIME::Type
+  content-type: audio/x-m4a
+  encoding: base64
+  extensions:
+  - m4a
 - !ruby/object:MIME::Type
   content-type: audio/MP4A-LATM
   encoding: base64