diff --git a/telethon/utils.py b/telethon/utils.py
index 74f90011..95bb65aa 100644
--- a/telethon/utils.py
+++ b/telethon/utils.py
@@ -51,6 +51,8 @@ mimetypes.add_type('audio/aac', '.aac')
 mimetypes.add_type('audio/ogg', '.ogg')
 mimetypes.add_type('audio/flac', '.flac')
 
+mimetypes.add_type('application/x-tgsticker', '.tgs')
+
 USERNAME_RE = re.compile(
     r'@|(?:https?://)?(?:www\.)?(?:telegram\.(?:me|dog)|t\.me)/(@|joinchat/)?'
 )