diff --git a/board/nm/nmhw21/board.c b/board/nm/nmhw21/board.c
index ed611d8c28..7a32bbcaa4 100644
--- a/board/nm/nmhw21/board.c
+++ b/board/nm/nmhw21/board.c
@@ -1298,6 +1298,8 @@ static int check_button(int time, bool button)
 	return act;
 }
 
+#if 0
+
 static int check_break_length(int time, bool rx_line)
 {
 	/*
@@ -1403,6 +1405,8 @@ static int check_break_length(int time, bool rx_line)
 	return act;
 }
 
+#endif
+
 static int check_break_command(int time, int has_input, int c)
 {
 	/*
@@ -1541,7 +1545,7 @@ static void check_reset_button(void)
 		a_[1] = NONE;
 		a_[2] = NONE;
 		a_[0] = check_button(counter, button);
-		a_[1] = check_break_length(counter, rx_line);
+		/* a_[1] = check_break_length(counter, rx_line); */
 		a_[2] = check_break_command(counter, has_input, c);
 
 		/* if all SMs are sure there is not action, stop here */