diff --git a/jupyter_server/services/kernels/handlers.py b/jupyter_server/services/kernels/handlers.py
index 0b2d102b9..158dcd8b6 100644
--- a/jupyter_server/services/kernels/handlers.py
+++ b/jupyter_server/services/kernels/handlers.py
@@ -159,7 +159,7 @@ def nudge(self):
         iopub_future = Future()
         both_done = gen.multi([info_future, iopub_future])
 
-        def finish(f=None):
+        def finish(_=None):
             """Ensure all futures are resolved
             which in turn triggers cleanup
             """
@@ -167,7 +167,7 @@ def finish(f=None):
                 if not f.done():
                     f.set_result(None)
 
-        def cleanup(f=None):
+        def cleanup(_=None):
             """Common cleanup"""
             loop.remove_timeout(nudge_handle)
             iopub_channel.stop_on_recv()
@@ -360,7 +360,7 @@ async def _register_session(self):
             await stale_handler.close()
         self._open_sessions[self.session_key] = self
 
-    async def open(self, kernel_id):
+    def open(self, kernel_id):
         super(ZMQChannelsHandler, self).open()
         km = self.kernel_manager
         km.notify_connect(kernel_id)