--- a/tile.h	Mon Feb 07 09:56:16 2005 +0000
+++ b/tile.h	Mon Feb 07 10:09:28 2005 +0000
@@ -57,8 +57,9 @@
 	return GetTileType(tile) == type;
 }
 
-static inline bool GetTileOwner(TileIndex tile)
+static inline Owner GetTileOwner(TileIndex tile)
 {
+	assert(tile < MapSize());
 	return _map_owner[tile];
 }