diff --git a/board/nm/nmhw21/board.c b/board/nm/nmhw21/board.c
index e5897680b5..382c2ad1d2 100644
--- a/board/nm/nmhw21/board.c
+++ b/board/nm/nmhw21/board.c
@@ -1518,6 +1518,7 @@ static void check_reset_button(void)
 		bool rx_line;
 		int has_input;
 		int c = -1;
+		int i;
 
 		/* Get state machine inputs */
 		button = get_button_state();
@@ -1546,7 +1547,7 @@ static void check_reset_button(void)
 		}
 
 		/* if one of the SMs has an action, stop here */
-		for (int i=0; i<3; i++) {
+		for (i=0; i<3; i++) {
 			if ((a_[i] == FACTORY_RESET) || (a_[i] == RECOVERY_BOOT)) {
 				action = a_[i];
 				break;