diff --git a/board/nm/netbird_v2/shield_comio.c b/board/nm/netbird_v2/shield_comio.c
index e9e1135af2..2efac38db2 100644
--- a/board/nm/netbird_v2/shield_comio.c
+++ b/board/nm/netbird_v2/shield_comio.c
@@ -221,6 +221,9 @@ static int get_mode_from_args(char * const argv[], int argc)
 			return -1;
 		}
 	}
+	else {
+		rs232 = 1;
+	}
 
 	/* Termination is inverse */
 	return (rs232 << 0) | ((!termination) << 1);