diff --git a/pkgs/development/python-modules/asyncssh/default.nix b/pkgs/development/python-modules/asyncssh/default.nix
index ef21cb001b49..76b863e24fb3 100644
--- a/pkgs/development/python-modules/asyncssh/default.nix
+++ b/pkgs/development/python-modules/asyncssh/default.nix
@@ -12,6 +12,9 @@ buildPythonPackage rec {
     sha256 = "a44736830741e2bb9c4e3992819288b77ac4af217a46d12f415bb57c18ed9c22";
   };
 
+  # See https://github.com/ronf/asyncssh/commit/6a92930e00f3bbc67d9cdf66816917e64f2450e9#r29559647
+  patches = ./mock_getnameinfo.patch;
+
   propagatedBuildInputs = [ 
     bcrypt
     cryptography
diff --git a/pkgs/development/python-modules/asyncssh/mock_getnameinfo.patch b/pkgs/development/python-modules/asyncssh/mock_getnameinfo.patch
new file mode 100644
index 000000000000..5e8f475445e7
--- /dev/null
+++ b/pkgs/development/python-modules/asyncssh/mock_getnameinfo.patch
@@ -0,0 +1,159 @@
+diff --git a/tests/server.py b/tests/server.py
+index fbd7e37..e7542dc 100644
+--- a/tests/server.py
++++ b/tests/server.py
+@@ -208,12 +208,10 @@ class ServerTestCase(AsyncTestCase):
+         cls._server = yield from cls.start_server()
+ 
+         sock = cls._server.sockets[0]
+-        cls._client_host, _ = yield from cls.loop.getnameinfo(('127.0.0.1', 0))
+         cls._server_addr = '127.0.0.1'
+         cls._server_port = sock.getsockname()[1]
+ 
+-        host = '[%s]:%d,%s ' % (cls._server_addr, cls._server_port,
+-                                cls._client_host)
++        host = '[%s]:%d,localhost ' % (cls._server_addr, cls._server_port)
+ 
+         with open('known_hosts', 'w') as known_hosts:
+             known_hosts.write(host)
+diff --git a/tests/test_auth_keys.py b/tests/test_auth_keys.py
+index 1d625ef..72a49f7 100644
+--- a/tests/test_auth_keys.py
++++ b/tests/test_auth_keys.py
+@@ -13,13 +13,13 @@
+ """Unit tests for matching against authorized_keys file"""
+ 
+ import unittest
+-from unittest.mock import patch
+ 
+ import asyncssh
+ 
+-from .util import TempDirTestCase, x509_available
++from .util import TempDirTestCase, patch_getnameinfo, x509_available
+ 
+ 
++@patch_getnameinfo
+ class _TestAuthorizedKeys(TempDirTestCase):
+     """Unit tests for auth_keys module"""
+ 
+@@ -69,36 +69,22 @@ class _TestAuthorizedKeys(TempDirTestCase):
+     def match_keys(self, tests, x509=False):
+         """Match against authorized keys"""
+ 
+-        def getnameinfo(sockaddr, flags):
+-            """Mock reverse DNS lookup of client address"""
+-
+-            # pylint: disable=unused-argument
+-
+-            host, port = sockaddr
+-
+-            if host == '127.0.0.1':
+-                return ('localhost', port)
+-            else:
+-                return sockaddr
+-
+-        with patch('socket.getnameinfo', getnameinfo):
+-            for keys, matches in tests:
+-                auth_keys = self.build_keys(keys, x509)
+-                for (msg, keynum, client_addr,
+-                     cert_principals, match) in matches:
+-                    with self.subTest(msg, x509=x509):
+-                        if x509:
+-                            result, trusted_cert = auth_keys.validate_x509(
+-                                self.imported_certlist[keynum], client_addr)
+-                            if (trusted_cert and trusted_cert.subject !=
+-                                    self.imported_certlist[keynum].subject):
+-                                result = None
+-                        else:
+-                            result = auth_keys.validate(
+-                                self.imported_keylist[keynum], client_addr,
+-                                cert_principals, keynum == 1)
+-
+-                        self.assertEqual(result is not None, match)
++        for keys, matches in tests:
++            auth_keys = self.build_keys(keys, x509)
++            for (msg, keynum, client_addr, cert_principals, match) in matches:
++                with self.subTest(msg, x509=x509):
++                    if x509:
++                        result, trusted_cert = auth_keys.validate_x509(
++                            self.imported_certlist[keynum], client_addr)
++                        if (trusted_cert and trusted_cert.subject !=
++                                self.imported_certlist[keynum].subject):
++                            result = None
++                    else:
++                        result = auth_keys.validate(
++                            self.imported_keylist[keynum], client_addr,
++                            cert_principals, keynum == 1)
++
++                    self.assertEqual(result is not None, match)
+ 
+     def test_matches(self):
+         """Test authorized keys matching"""
+diff --git a/tests/test_connection_auth.py b/tests/test_connection_auth.py
+index 3da8a5b..ff3e3cc 100644
+--- a/tests/test_connection_auth.py
++++ b/tests/test_connection_auth.py
+@@ -23,8 +23,8 @@ from asyncssh.packet import String
+ from asyncssh.public_key import CERT_TYPE_USER, CERT_TYPE_HOST
+ 
+ from .server import Server, ServerTestCase
+-from .util import asynctest, gss_available, patch_gss, make_certificate
+-from .util import x509_available
++from .util import asynctest, gss_available, patch_getnameinfo, patch_gss
++from .util import make_certificate, x509_available
+ 
+ 
+ class _FailValidateHostSSHServerConnection(asyncssh.SSHServerConnection):
+@@ -455,6 +455,7 @@ class _TestGSSFQDN(ServerTestCase):
+         yield from conn.wait_closed()
+ 
+ 
++@patch_getnameinfo
+ class _TestHostBasedAuth(ServerTestCase):
+     """Unit tests for host-based authentication"""
+ 
+@@ -579,7 +580,7 @@ class _TestHostBasedAuth(ServerTestCase):
+         """Test stripping of trailing dot from client host"""
+ 
+         with (yield from self.connect(username='user', client_host_keys='skey',
+-                                      client_host=self._client_host + '.',
++                                      client_host='localhost.',
+                                       client_username='user')) as conn:
+             pass
+ 
+@@ -667,6 +668,7 @@ class _TestHostBasedAsyncServerAuth(_TestHostBasedAuth):
+                                     client_username='user')
+ 
+ 
++@patch_getnameinfo
+ class _TestLimitedHostBasedSignatureAlgs(ServerTestCase):
+     """Unit tests for limited host key signature algorithms"""
+ 
+diff --git a/tests/util.py b/tests/util.py
+index 42bb596..4d92ec3 100644
+--- a/tests/util.py
++++ b/tests/util.py
+@@ -84,6 +84,24 @@ def asynctest35(func):
+     return async_wrapper
+ 
+ 
++def patch_getnameinfo(cls):
++    """Decorator for patching socket.getnameinfo"""
++
++    def getnameinfo(sockaddr, flags):
++        """Mock reverse DNS lookup of client address"""
++
++        # pylint: disable=unused-argument
++
++        host, port = sockaddr
++
++        if host == '127.0.0.1':
++            return ('localhost', port)
++        else:
++            return sockaddr
++
++    return patch('socket.getnameinfo', getnameinfo)(cls)
++
++
+ def patch_gss(cls):
+     """Decorator for patching GSSAPI classes"""