diff --git a/src/genworld.cpp b/src/genworld.cpp
--- a/src/genworld.cpp
+++ b/src/genworld.cpp
@@ -120,8 +120,8 @@ static void _GenerateWorld(void *)
 
 			/* Make sure the tiles at the north border are void tiles if needed. */
 			if (_settings_game.construction.freeform_edges) {
-				for (uint row = 0; row < MapSizeY(); row++) MakeVoid(TileXY(0, row));
-				for (uint col = 0; col < MapSizeX(); col++) MakeVoid(TileXY(col, 0));
+				for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
+				for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
 			}
 
 			/* Make the map the height of the setting */
diff --git a/src/landscape.cpp b/src/landscape.cpp
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -841,22 +841,17 @@ void RunTileLoop()
 
 void InitializeLandscape()
 {
-	uint maxx = MapMaxX();
-	uint maxy = MapMaxY();
-	uint sizex = MapSizeX();
+	for (uint y = _settings_game.construction.freeform_edges ? 1 : 0; y < MapMaxY(); y++) {
+		for (uint x = _settings_game.construction.freeform_edges ? 1 : 0; x < MapMaxX(); x++) {
+			MakeClear(TileXY(x, y), CLEAR_GRASS, 3);
+			SetTileHeight(TileXY(x, y), 0);
+			SetTropicZone(TileXY(x, y), TROPICZONE_NORMAL);
+			ClearBridgeMiddle(TileXY(x, y));
+		}
+	}
 
-	uint y;
-	for (y = _settings_game.construction.freeform_edges ? 1 : 0; y < maxy; y++) {
-		uint x;
-		for (x = _settings_game.construction.freeform_edges ? 1 : 0; x < maxx; x++) {
-			MakeClear(sizex * y + x, CLEAR_GRASS, 3);
-			SetTileHeight(sizex * y + x, 0);
-			SetTropicZone(sizex * y + x, TROPICZONE_NORMAL);
-			ClearBridgeMiddle(sizex * y + x);
-		}
-		MakeVoid(sizex * y + x);
-	}
-	for (uint x = 0; x < sizex; x++) MakeVoid(sizex * y + x);
+	for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, MapMaxY()));
+	for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(MapMaxX(), y));
 }
 
 static const byte _genterrain_tbl_1[5] = { 10, 22, 33, 37, 4  };
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -204,10 +204,8 @@ static void UpdateCurrencies()
  */
 static void UpdateVoidTiles()
 {
-	uint i;
-
-	for (i = 0; i < MapMaxY(); ++i) MakeVoid(i * MapSizeX() + MapMaxX());
-	for (i = 0; i < MapSizeX(); ++i) MakeVoid(MapSizeX() * MapMaxY() + i);
+	for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, MapMaxY()));
+	for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(MapMaxX(), y));
 }
 
 static inline RailType UpdateRailType(RailType rt, RailType min)
diff --git a/src/settings.cpp b/src/settings.cpp
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1222,8 +1222,8 @@ static bool CheckFreeformEdges(int32 p1)
 				return false;
 			}
 		}
-		for (uint i = 0; i < MapSizeX(); i++) MakeVoid(TileXY(i, 0));
-		for (uint i = 0; i < MapSizeY(); i++) MakeVoid(TileXY(0, i));
+		for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
+		for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
 	} else {
 		for (uint i = 0; i < MapMaxX(); i++) {
 			if (TileHeight(TileXY(i, 1)) != 0) {
diff --git a/src/tgp.cpp b/src/tgp.cpp
--- a/src/tgp.cpp
+++ b/src/tgp.cpp
@@ -995,8 +995,8 @@ void GenerateTerrainPerlin()
 
 	/* First make sure the tiles at the north border are void tiles if needed. */
 	if (_settings_game.construction.freeform_edges) {
-		for (int y = 0; y < _height_map.size_y - 1; y++) MakeVoid(_height_map.size_x * y);
-		for (int x = 0; x < _height_map.size_x;     x++) MakeVoid(x);
+		for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
+		for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
 	}
 
 	int max_height = H2I(TGPGetMaxHeight());