diff --git a/libmproxy/proxy.py b/libmproxy/proxy.py
index 63f4ceb46..eefa69059 100644
--- a/libmproxy/proxy.py
+++ b/libmproxy/proxy.py
@@ -468,6 +468,7 @@ class ProxyHandler(SocketServer.StreamRequestHandler):
 
 
 ServerBase = SocketServer.ThreadingTCPServer
+ServerBase.daemon_threads = True        # Terminate workers when main thread terminates
 class ProxyServer(ServerBase):
     request_queue_size = 20
     allow_reuse_address = True