diff --git a/src/xpra/server/server_core.py b/src/xpra/server/server_core.py
index b20bbbbf55..32ad9ed314 100644
--- a/src/xpra/server/server_core.py
+++ b/src/xpra/server/server_core.py
@@ -685,30 +685,31 @@ def start_websockify(self, conn, frominfo):
         from xpra.net.websocket import WebSocketConnection, WSRequestHandler
         try:
             sock = conn._socket
-            #set the websocket to non-blocking because:
-            # * win32 servers don't seem to honour our request to use blocking sockets anyway
-            #   (this should not be needed on any other platform,
-            #   maybe this should go in websockify somewhere instead)
-            # * the proxy server needs this to steal the connection
+            # win32 servers don't seem to honour our request to use blocking sockets
+            # (this workaround should not be needed on any other platform,
+            #  and maybe this should go in websockify somewhere instead)
             from xpra.net.bytestreams import untilConcludes
-            saved_recv = sock.recv
-            saved_send = sock.send
-            def recv(*args):
-                return untilConcludes(conn.is_active, saved_recv, *args)
-            def send(*args):
-                return untilConcludes(conn.is_active, saved_send, *args)
-            sock.recv = recv
-            sock.send = send
-            def new_websocket_client(wsh):
-                netlog("new_websocket_client(%s) socket=%s", wsh, sock)
-                wsc = WebSocketConnection(sock, conn.local, conn.remote, conn.target, conn.socktype, wsh)
-                #now we can have a "is_active" that belongs to the real connection object:
+            WIN32 = sys.platform.startswith("win")
+            if WIN32:
+                saved_recv = sock.recv
+                saved_send = sock.send
                 def recv(*args):
-                    return untilConcludes(wsc.is_active, saved_recv, *args)
+                    return untilConcludes(conn.is_active, saved_recv, *args)
                 def send(*args):
-                    return untilConcludes(wsc.is_active, saved_send, *args)
+                    return untilConcludes(conn.is_active, saved_send, *args)
                 sock.recv = recv
                 sock.send = send
+            def new_websocket_client(wsh):
+                netlog("new_websocket_client(%s) socket=%s", wsh, sock)
+                wsc = WebSocketConnection(sock, conn.local, conn.remote, conn.target, conn.socktype, wsh)
+                if WIN32:
+                    #now we can have a "is_active" that belongs to the real connection object:
+                    def recv(*args):
+                        return untilConcludes(wsc.is_active, saved_recv, *args)
+                    def send(*args):
+                        return untilConcludes(wsc.is_active, saved_send, *args)
+                    sock.recv = recv
+                    sock.send = send
                 self.make_protocol("tcp", wsc, frominfo)
             WSRequestHandler(sock, frominfo, new_websocket_client, self._www_dir)
             return