diff --git a/trezor_agent/server.py b/trezor_agent/server.py
index 5680614..d4059ac 100644
--- a/trezor_agent/server.py
+++ b/trezor_agent/server.py
@@ -1,5 +1,6 @@
 """UNIX-domain socket server for ssh-agent implementation."""
 import contextlib
+import functools
 import logging
 import os
 import socket
@@ -77,7 +78,7 @@ def retry(func, exception_type, quit_event):
             pass
 
 
-def server_thread(sock, handler, quit_event):
+def server_thread(sock, handle_conn, quit_event):
     """Run a server on the specified socket."""
     log.debug('server thread started')
 
@@ -94,7 +95,7 @@ def server_thread(sock, handler, quit_event):
             log.debug('server stopped')
             break
         with contextlib.closing(conn):
-            handle_connection(conn, handler)
+            handle_conn(conn)
     log.debug('server thread stopped')
 
 
@@ -122,7 +123,10 @@ def serve(handler, sock_path=None, timeout=UNIX_SOCKET_TIMEOUT):
     with unix_domain_socket_server(sock_path) as sock:
         sock.settimeout(timeout)
         quit_event = threading.Event()
-        kwargs = dict(sock=sock, handler=handler, quit_event=quit_event)
+        handle_conn = functools.partial(handle_connection, handler=handler)
+        kwargs = dict(sock=sock,
+                      handle_conn=handle_conn,
+                      quit_event=quit_event)
         with spawn(server_thread, kwargs):
             try:
                 yield environ
diff --git a/trezor_agent/tests/test_server.py b/trezor_agent/tests/test_server.py
index 31487e6..af7f27d 100644
--- a/trezor_agent/tests/test_server.py
+++ b/trezor_agent/tests/test_server.py
@@ -1,3 +1,4 @@
+import functools
 import io
 import os
 import socket
@@ -78,8 +79,10 @@ def test_server_thread():
         def getsockname(self):  # pylint: disable=no-self-use
             return 'fake_server'
 
+    handler = protocol.Handler(keys=[], signer=None),
+    handle_conn = functools.partial(server.handle_connection, handler=handler)
     server.server_thread(sock=FakeServer(),
-                         handler=protocol.Handler(keys=[], signer=None),
+                         handle_conn=handle_conn,
                          quit_event=quit_event)