diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index f3343c80545..d2c8ac76dcc 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -481,10 +481,19 @@ def _default_mime_types():
         '.wsdl'   : 'application/xml',
         '.xpdl'   : 'application/xml',
         '.zip'    : 'application/zip',
+        '.3gp'    : 'audio/3gpp',
+        '.3gpp'   : 'audio/3gpp',
+        '.3g2'    : 'audio/3gpp2',
+        '.3gpp2'  : 'audio/3gpp2',
+        '.aac'    : 'audio/aac',
+        '.adts'   : 'audio/aac',
+        '.loas'   : 'audio/aac',
+        '.ass'    : 'audio/aac',
         '.au'     : 'audio/basic',
         '.snd'    : 'audio/basic',
         '.mp3'    : 'audio/mpeg',
         '.mp2'    : 'audio/mpeg',
+        '.opus'   : 'audio/opus',
         '.aif'    : 'audio/x-aiff',
         '.aifc'   : 'audio/x-aiff',
         '.aiff'   : 'audio/x-aiff',
diff --git a/Misc/NEWS.d/next/Library/2021-01-21-16-58-34.bpo-42994.El0Ksp.rst b/Misc/NEWS.d/next/Library/2021-01-21-16-58-34.bpo-42994.El0Ksp.rst
new file mode 100644
index 00000000000..40f85479421
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-01-21-16-58-34.bpo-42994.El0Ksp.rst
@@ -0,0 +1 @@
+Add MIME types for opus, AAC, 3gpp and 3gpp2