diff --git a/tncattach.c b/tncattach.c
index 30e9a25..85d80ee 100644
--- a/tncattach.c
+++ b/tncattach.c
@@ -564,6 +564,7 @@ int main(int argc, char **argv) {
     arguments.noup = false;
     arguments.id_interval = -1;
     arguments.valid_id = false;
+    arguments.kiss_over_tcp = false;
 
     argp_parse(&argp, argc, argv, 0, 0, &arguments);