1 files changed, 1 insertions, 1 deletions
diff --git a/src/gui.h b/src/gui.h
index 591819c8c..afee0f3ac 100644
--- a/src/gui.h
+++ b/src/gui.h
@@ -92,7 +92,7 @@ void ShowEstimatedCostOrIncome(Money cost, int x, int y);
 void ShowErrorMessage(StringID msg_1, StringID msg_2, int x, int y);
 
 void ShowSmallMap();
-void ShowExtraViewPortWindow();
+void ShowExtraViewPortWindow(TileIndex tile = INVALID_TILE);
 void SetVScrollCount(Window *w, int num);
 void SetVScroll2Count(Window *w, int num);
 void SetHScrollCount(Window *w, int num);