diff --git a/src/interface/window.h b/src/interface/window.h
index fa7d8a75a8..c97f68c45c 100644
--- a/src/interface/window.h
+++ b/src/interface/window.h
@@ -574,6 +574,7 @@ rct_window *window_get_main();
 void window_scroll_to_viewport(rct_window *w);
 void window_scroll_to_location(rct_window *w, int x, int y, int z);
 void window_rotate_camera(rct_window *w, int direction);
+void window_viewport_get_map_coords_by_cursor(rct_window *w, sint16 *map_x, sint16 *map_y);
 void window_zoom_set(rct_window *w, int zoomLevel);
 void window_zoom_in(rct_window *w);
 void window_zoom_out(rct_window *w);