diff --git a/src/testdir/test_channel.py b/src/testdir/test_channel.py
index 36aad2b..b0c3140 100644
--- a/src/testdir/test_channel.py
+++ b/src/testdir/test_channel.py
@@ -22,7 +22,8 @@
 class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler):
 
     def setup(self):
-        self.request.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
+        if self.server.address_family != socket.AF_UNIX:
+            self.request.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
 
     def handle(self):
         print("=== socket opened ===")