diff --git a/Lib/socketserver.py b/Lib/socketserver.py
index 9409e554240..d19146f28fe 100644
--- a/Lib/socketserver.py
+++ b/Lib/socketserver.py
@@ -566,7 +566,7 @@ def process_request(self, request, client_address):
         t = threading.Thread(target = self.process_request_thread,
                              args = (request, client_address))
         if self.daemon_threads:
-            t.set_daemon(True)
+            t.daemon = True
         t.start()