diff --git a/examples/userlog.lua b/examples/userlog.lua
index 55aa0952..3a8c5d22 100644
--- a/examples/userlog.lua
+++ b/examples/userlog.lua
@@ -6,7 +6,17 @@ skynet.register_protocol {
 	id = skynet.PTYPE_TEXT,
 	unpack = skynet.tostring,
 	dispatch = function(_, address, msg)
-		print(string.format("%x(%.2f): %s", address, skynet.time(), msg))
+		print(string.format(":%08x(%.2f): %s", address, skynet.time(), msg))
+	end
+}
+
+skynet.register_protocol {
+	name = "SYSTEM",
+	id = skynet.PTYPE_SYSTEM,
+	unpack = function(...) return ... end,
+	dispatch = function()
+		-- reopen signal
+		print("SIGHUP")
 	end
 }