--- a/mercurial/sshpeer.py	Mon Dec 16 02:41:24 2024 -0500
+++ b/mercurial/sshpeer.py	Mon Dec 16 03:04:44 2024 -0500
@@ -8,6 +8,7 @@
 from __future__ import annotations
 
 import re
+import typing
 import uuid
 
 from .i18n import _
@@ -25,6 +26,11 @@
     urlutil,
 )
 
+if typing.TYPE_CHECKING:
+    from typing import (
+        Set,
+    )
+
 
 def _serverquote(s):
     """quote a string for the remote shell ... which we assume is sh"""
@@ -441,7 +447,7 @@
 
     # Begin of ipeercapabilities interface.
 
-    def capabilities(self):
+    def capabilities(self) -> Set[bytes]:
         return self._caps
 
     # End of ipeercapabilities interface.