diff -r cd36b16f6b35 -r 7eb6fa9b03fd mod_net_proxy/mod_net_proxy.lua
--- a/mod_net_proxy/mod_net_proxy.lua	Sun Apr 01 22:41:40 2018 +0200
+++ b/mod_net_proxy/mod_net_proxy.lua	Sun Apr 01 22:43:15 2018 +0200
@@ -159,6 +159,7 @@
 	local _, err = ip.new_ip(src_addr);
 	if err ~= nil then
 		module:log("warn", "Received unparseable PROXYv1 source address from %s: %s", conn:ip(), src_addr);
+		return PROTO_HANDLER_STATUS.FAILURE, nil;
 	end
 	_, err = ip.new_ip(dst_addr);
 	if err ~= nil then