diff --git a/src/openrct2/interface/colour.h b/src/openrct2/interface/colour.h
index da1af7f4e6..e89c4a352b 100644
--- a/src/openrct2/interface/colour.h
+++ b/src/openrct2/interface/colour.h
@@ -121,8 +121,6 @@ enum {
 #define NOT_TRANSLUCENT(x) ((x) & ~COLOUR_FLAG_TRANSLUCENT)
 #define BASE_COLOUR(x)          ((x) & 0x1F)
 
-#define NUM_COLOURS 32
-
 typedef struct rct_colour_map {
     uint8 colour_0;
     uint8 colour_1;