diff --git a/daphne/testing.py b/daphne/testing.py
index 2e604554..ab5729e2 100644
--- a/daphne/testing.py
+++ b/daphne/testing.py
@@ -186,7 +186,7 @@ def run(self):
                 application=application,
                 endpoints=endpoints,
                 signal_handlers=False,
-                **self.kwargs
+                **self.kwargs,
             )
             # Set up a poller to look for the port
             reactor.callLater(0.1, self.resolve_port)
diff --git a/setup.cfg b/setup.cfg
index 9c0374ba..e8f4d5e8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -42,6 +42,7 @@ console_scripts =
 [options.extras_require]
 tests =
     django
+    httpunixsocketconnection
     hypothesis
     pytest
     pytest-asyncio
diff --git a/tests/http_base.py b/tests/http_base.py
index e5a80c21..8d483b8c 100644
--- a/tests/http_base.py
+++ b/tests/http_base.py
@@ -17,6 +17,20 @@ class DaphneTestCase(unittest.TestCase):
     to store/retrieve the request/response messages.
     """
 
+    _instance_endpoint_args = {}
+
+    @staticmethod
+    def _get_instance_raw_socket_connection(test_app, *, timeout):
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.settimeout(timeout)
+        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        s.connect((test_app.host, test_app.port))
+        return s
+
+    @staticmethod
+    def _get_instance_http_connection(test_app, *, timeout):
+        return HTTPConnection(test_app.host, test_app.port, timeout=timeout)
+
     ### Plain HTTP helpers
 
     def run_daphne_http(
@@ -36,13 +50,15 @@ def run_daphne_http(
         and response messages.
         """
         with DaphneTestingInstance(
-            xff=xff, request_buffer_size=request_buffer_size
+            xff=xff,
+            request_buffer_size=request_buffer_size,
+            **self._instance_endpoint_args,
         ) as test_app:
             # Add the response messages
             test_app.add_send_messages(responses)
             # Send it the request. We have to do this the long way to allow
             # duplicate headers.
-            conn = HTTPConnection(test_app.host, test_app.port, timeout=timeout)
+            conn = self._get_instance_http_connection(test_app, timeout=timeout)
             if params:
                 path += "?" + parse.urlencode(params, doseq=True)
             conn.putrequest(method, path, skip_accept_encoding=True, skip_host=True)
@@ -74,13 +90,10 @@ def run_daphne_raw(self, data, *, responses=None, timeout=1):
         Returns what Daphne sends back.
         """
         assert isinstance(data, bytes)
-        with DaphneTestingInstance() as test_app:
+        with DaphneTestingInstance(**self._instance_endpoint_args) as test_app:
             if responses is not None:
                 test_app.add_send_messages(responses)
-            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            s.settimeout(timeout)
-            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            s.connect((test_app.host, test_app.port))
+            s = self._get_instance_raw_socket_connection(test_app, timeout=timeout)
             s.send(data)
             try:
                 return s.recv(1000000)
diff --git a/tests/test_unixsocket.py b/tests/test_unixsocket.py
new file mode 100644
index 00000000..4f991fde
--- /dev/null
+++ b/tests/test_unixsocket.py
@@ -0,0 +1,52 @@
+import os
+import socket
+import weakref
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest import skipUnless
+
+import test_http_response
+from http_base import DaphneTestCase
+
+from httpunixsocketconnection import HTTPUnixSocketConnection
+
+
+__all__ = ["UnixSocketFDDaphneTestCase", "TestInheritedUnixSocket"]
+
+
+class UnixSocketFDDaphneTestCase(DaphneTestCase):
+    @property
+    def _instance_endpoint_args(self):
+        tmp_dir = TemporaryDirectory()
+        weakref.finalize(self, tmp_dir.cleanup)
+        sock_path = str(Path(tmp_dir.name, "test.sock"))
+        listen_sock = socket.socket(socket.AF_UNIX, type=socket.SOCK_STREAM)
+        listen_sock.bind(sock_path)
+        listen_sock.listen()
+        listen_sock_fileno = os.dup(listen_sock.fileno())
+        os.set_inheritable(listen_sock_fileno, True)
+        listen_sock.close()
+        return {"host": None, "file_descriptor": listen_sock_fileno}
+
+    @staticmethod
+    def _get_instance_socket_path(test_app):
+        with socket.socket(fileno=os.dup(test_app.file_descriptor)) as sock:
+            return sock.getsockname()
+
+    @classmethod
+    def _get_instance_raw_socket_connection(cls, test_app, *, timeout):
+        socket_name = cls._get_instance_socket_path(test_app)
+        s = socket.socket(socket.AF_UNIX, type=socket.SOCK_STREAM)
+        s.settimeout(timeout)
+        s.connect(socket_name)
+        return s
+
+    @classmethod
+    def _get_instance_http_connection(cls, test_app, *, timeout):
+        socket_name = cls._get_instance_socket_path(test_app)
+        return HTTPUnixSocketConnection(unix_socket=socket_name, timeout=timeout)
+
+
+@skipUnless(hasattr(socket, "AF_UNIX"), "AF_UNIX support not present.")
+class TestInheritedUnixSocket(UnixSocketFDDaphneTestCase):
+    test_minimal_response = test_http_response.TestHTTPResponse.test_minimal_response