diff --git a/4x4_matrix_part_1/main.c b/4x4_matrix_part_1/main.c
index f287c21..1dd1cc2 100644
--- a/4x4_matrix_part_1/main.c
+++ b/4x4_matrix_part_1/main.c
@@ -15,6 +15,8 @@
 #include "main.h"
 #include "digital_slow.h"
 
+#define __DELAY_BACKWARD_COMPATIBLE__
+
 uint8_t column_pins[4] = {2, 3, 4, 5};
 uint8_t row_pins[4]    = {11, 10, 9, 8};
 uint8_t pattern[4][4]  = {{1,0,0,1},