diff --git a/src/crt.h b/src/crt.h
index c284749..783e86a 100644
--- a/src/crt.h
+++ b/src/crt.h
@@ -4,6 +4,8 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#define CRT_FRAMES_PER_SECOND 50
+
 void crt_waitNextFrame(void);
 void crt_waitFrames(uint16_t n);