diff --git a/socket_spec.h b/socket_spec.h
index 7cc2fac..94719c8 100644
--- a/socket_spec.h
+++ b/socket_spec.h
@@ -31,3 +31,5 @@
 
 bool parse_tcp_socket_spec(std::string_view spec, std::string* hostname, int* port,
                            std::string* serial, std::string* error);
+
+int get_host_socket_spec_port(std::string_view spec, std::string* error);