diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index f3343c805452d0..0c82539fbfbbfc 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -485,6 +485,7 @@ def _default_mime_types():
         '.snd'    : 'audio/basic',
         '.mp3'    : 'audio/mpeg',
         '.mp2'    : 'audio/mpeg',
+        '.weba'   : 'audio/webm',
         '.aif'    : 'audio/x-aiff',
         '.aifc'   : 'audio/x-aiff',
         '.aiff'   : 'audio/x-aiff',
diff --git a/Lib/test/mime.types b/Lib/test/mime.types
index 68724430c8a3fd..a9583817fd7191 100644
--- a/Lib/test/mime.types
+++ b/Lib/test/mime.types
@@ -1401,6 +1401,7 @@ application/x-xpinstall				xpi
 application/x-xspf+xml				xspf
 application/x-xz				xz
 audio/midi					mid midi kar
+audio/webm					weba
 audio/x-aiff					aif aiff aifc
 audio/x-annodex					axa
 audio/x-flac					flac