diff --git a/telethon/utils.py b/telethon/utils.py
index 26b48c59..9b485b38 100644
--- a/telethon/utils.py
+++ b/telethon/utils.py
@@ -43,7 +43,7 @@ mimetypes.add_type('video/mp4', '.mp4')
 mimetypes.add_type('video/quicktime', '.mov')
 mimetypes.add_type('video/avi', '.avi')
 
-mimetypes.add_type('audio/mp3', '.mp3')
+mimetypes.add_type('audio/mpeg', '.mp3')
 mimetypes.add_type('audio/m4a', '.m4a')
 mimetypes.add_type('audio/aac', '.aac')
 mimetypes.add_type('audio/ogg', '.ogg')