diff --git a/config.h b/config.h
index 75a8b5b..d43d672 100644
--- a/config.h
+++ b/config.h
@@ -1,6 +1,8 @@
 #ifndef CONFIG_H
 #define CONFIG_H
 
+#include "math.h"
+
 #define BAUDRATE (9600)
 
 // Pins
@@ -27,8 +29,8 @@
 #define PIN_LASER (PIN_PD2)
 
 // Magic numbers
-#define STEP_RATIO_X (7020)
-#define STEP_RATIO_Y (7020)
+#define STEP_RATIO_X (6432 / M_PI)
+#define STEP_RATIO_Y (6432 / M_PI)
 
 // Offset [cm]
 #define OFFSET_X (0)