diff --git a/webrtc/signalling/simple-server.py b/webrtc/signalling/simple-server.py
index df83c768fd..e46f748550 100755
--- a/webrtc/signalling/simple-server.py
+++ b/webrtc/signalling/simple-server.py
@@ -18,7 +18,8 @@ import argparse
 from concurrent.futures._base import TimeoutError
 
 parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
-parser.add_argument('--addr', default='0.0.0.0', help='Address to listen on')
+# See: host, port in https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.create_server
+parser.add_argument('--addr', default='', help='Address to listen on (default: all interfaces, both ipv4 and ipv6)')
 parser.add_argument('--port', default=8443, type=int, help='Port to listen on')
 parser.add_argument('--keepalive-timeout', dest='keepalive_timeout', default=30, type=int, help='Timeout for keepalive (in seconds)')
 parser.add_argument('--cert-path', default=os.path.dirname(__file__))