diff --git a/distribution/openrct2.d.ts b/distribution/openrct2.d.ts
index f97bb8c4d8..3bd0bbb156 100644
--- a/distribution/openrct2.d.ts
+++ b/distribution/openrct2.d.ts
@@ -1544,6 +1544,7 @@ declare global {
         object: number;
         primaryColour: number;
         secondaryColour: number;
+        tertiaryColour: number;
         quadrant: number;
         age: number;
     }