diff --git a/viewport.c b/viewport.c
index 041d2b2862..2120968233 100644
--- a/viewport.c
+++ b/viewport.c
@@ -109,6 +109,7 @@ static ViewportDrawer *_cur_vd;
 TileHighlightData _thd;
 static TileInfo *_cur_ti;
 
+extern void SmallMapCenterOnCurrentPos(Window *w);
 
 static Point MapXYZToViewport(const ViewPort *vp, uint x, uint y, uint z)
 {