diff --git a/src/disaster_cmd.cpp b/src/disaster_cmd.cpp
index 5205aa076d..8ef01cf959 100644
--- a/src/disaster_cmd.cpp
+++ b/src/disaster_cmd.cpp
@@ -682,10 +682,12 @@ static void DisasterTick_Big_Ufo_Destroyer(Vehicle *v)
 				EV_EXPLOSION_SMALL);
 		}
 
-		BEGIN_TILE_LOOP(tile, 6, 6, v->tile - TileDiffXY(3, 3))
-			tile = TILE_MASK(tile);
-			DisasterClearSquare(tile);
-		END_TILE_LOOP(tile, 6, 6, v->tile - TileDiffXY(3, 3))
+		for (int dy = -3; dy < 3; dy++) {
+			for (int dx = -3; dx < 3; dx++) {
+				TileIndex tile = TileAddWrap(v->tile, dx, dy);
+				if (tile != INVALID_TILE) DisasterClearSquare(tile);
+			}
+		}
 	}
 }
 
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index a8fe22914a..f4d559bb2a 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -928,7 +928,7 @@ static void PlantFarmField(TileIndex tile, IndustryID industry)
 	/* check the amount of bad tiles */
 	count = 0;
 	BEGIN_TILE_LOOP(cur_tile, size_x, size_y, tile)
-		cur_tile = TILE_MASK(cur_tile);
+		TILE_ASSERT(cur_tile);
 		count += IsBadFarmFieldTile(cur_tile);
 	END_TILE_LOOP(cur_tile, size_x, size_y, tile)
 	if (count * 2 >= size_x * size_y) return;
@@ -940,7 +940,7 @@ static void PlantFarmField(TileIndex tile, IndustryID industry)
 
 	/* make field */
 	BEGIN_TILE_LOOP(cur_tile, size_x, size_y, tile)
-		cur_tile = TILE_MASK(cur_tile);
+		TILE_ASSERT(cur_tile);
 		if (!IsBadFarmFieldTile2(cur_tile)) {
 			MakeField(cur_tile, field_type, industry);
 			SetClearCounter(cur_tile, counter);
diff --git a/src/landscape.cpp b/src/landscape.cpp
index 998a552d4e..15d70bbfd7 100644
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -830,8 +830,8 @@ static void CreateDesertOrRainForest()
 
 		for (data = _make_desert_or_rainforest_data;
 				data != endof(_make_desert_or_rainforest_data); ++data) {
-			TileIndex t = TILE_MASK(tile + ToTileIndexDiff(*data));
-			if (TileHeight(t) >= 4 || IsTileType(t, MP_WATER)) break;
+			TileIndex t = AddTileIndexDiffCWrap(tile, *data);
+			if (t != INVALID_TILE && (TileHeight(t) >= 4 || IsTileType(t, MP_WATER))) break;
 		}
 		if (data == endof(_make_desert_or_rainforest_data))
 			SetTropicZone(tile, TROPICZONE_DESERT);
@@ -848,8 +848,8 @@ static void CreateDesertOrRainForest()
 
 		for (data = _make_desert_or_rainforest_data;
 				data != endof(_make_desert_or_rainforest_data); ++data) {
-			TileIndex t = TILE_MASK(tile + ToTileIndexDiff(*data));
-			if (IsTileType(t, MP_CLEAR) && IsClearGround(t, CLEAR_DESERT)) break;
+			TileIndex t = AddTileIndexDiffCWrap(tile, *data);
+			if (t != INVALID_TILE && IsTileType(t, MP_CLEAR) && IsClearGround(t, CLEAR_DESERT)) break;
 		}
 		if (data == endof(_make_desert_or_rainforest_data))
 			SetTropicZone(tile, TROPICZONE_RAINFOREST);
diff --git a/src/newgrf_commons.cpp b/src/newgrf_commons.cpp
index b96d6aedfb..266d801ac2 100644
--- a/src/newgrf_commons.cpp
+++ b/src/newgrf_commons.cpp
@@ -292,7 +292,7 @@ TileIndex GetNearbyTile(byte parameter, TileIndex tile)
 	/* Swap width and height depending on axis for railway stations */
 	if (IsRailwayStationTile(tile) && GetRailStationAxis(tile) == AXIS_Y) Swap(x, y);
 
-	/* Make sure we never roam outside of the map */
+	/* Make sure we never roam outside of the map, better wrap in that case */
 	return TILE_MASK(tile + TileDiffXY(x, y));
 }
 
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 1facc4edf1..8c3b1c7377 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -124,7 +124,8 @@ static int CountMapSquareAround(TileIndex tile, CMSAMatcher cmp)
 
 	for (int dx = -3; dx <= 3; dx++) {
 		for (int dy = -3; dy <= 3; dy++) {
-			if (cmp(TILE_MASK(tile + TileDiffXY(dx, dy)))) num++;
+			TileIndex t = TileAddWrap(tile, dx, dy);
+			if (t != INVALID_TILE && cmp(t)) num++;
 		}
 	}
 
@@ -2956,52 +2957,27 @@ void FindStationsAroundTiles(TileIndex tile, int w_prod, int h_prod, StationList
 {
 	/* area to search = producer plus station catchment radius */
 	int max_rad = (_settings_game.station.modified_catchment ? MAX_CATCHMENT : CA_UNMODIFIED);
-	int w = w_prod + 2 * max_rad;
-	int h = h_prod + 2 * max_rad;
 
-	BEGIN_TILE_LOOP(cur_tile, w, h, tile - TileDiffXY(max_rad, max_rad))
-		cur_tile = TILE_MASK(cur_tile);
-		if (!IsTileType(cur_tile, MP_STATION)) continue;
+	for (int dy = -max_rad; dy < h_prod + max_rad; dy++) {
+		for (int dx = -max_rad; dx < w_prod + max_rad; dx++) {
+			TileIndex cur_tile = TileAddWrap(tile, dx, dy);
+			if (cur_tile == INVALID_TILE || !IsTileType(cur_tile, MP_STATION)) continue;
 
-		Station *st = GetStationByTile(cur_tile);
+			Station *st = GetStationByTile(cur_tile);
 
-		if (st->IsBuoy()) continue; // bouys don't accept cargo
+			if (st->IsBuoy()) continue; // bouys don't accept cargo
 
-
-		if (_settings_game.station.modified_catchment) {
-			/* min and max coordinates of the producer relative */
-			const int x_min_prod = max_rad + 1;
-			const int x_max_prod = max_rad + w_prod;
-			const int y_min_prod = max_rad + 1;
-			const int y_max_prod = max_rad + h_prod;
-
-			int rad = st->GetCatchmentRadius();
-
-			int x_dist = min(w_cur - x_min_prod, x_max_prod - w_cur);
-			if (w_cur < x_min_prod) {
-				x_dist = x_min_prod - w_cur;
-			} else if (w_cur > x_max_prod) {
-				x_dist = w_cur - x_max_prod;
+			if (_settings_game.station.modified_catchment) {
+				int rad = st->GetCatchmentRadius();
+				if (dx < -rad || dx >= rad + w_prod || dy < -rad || dy >= rad + h_prod) continue;
 			}
 
-			if (x_dist > rad) continue;
-
-			int y_dist = min(h_cur - y_min_prod, y_max_prod - h_cur);
-			if (h_cur < y_min_prod) {
-				y_dist = y_min_prod - h_cur;
-			} else if (h_cur > y_max_prod) {
-				y_dist = h_cur - y_max_prod;
-			}
-
-			if (y_dist > rad) continue;
+			/* Insert the station in the set. This will fail if it has
+			 * already been added.
+			 */
+			stations->Include(st);
 		}
-
-		/* Insert the station in the set. This will fail if it has
-		 * already been added.
-		 */
-		stations->Include(st);
-
-	END_TILE_LOOP(cur_tile, w, h, tile - TileDiffXY(max_rad, max_rad))
+	}
 }
 
 uint MoveGoodsToStation(TileIndex tile, int w, int h, CargoID type, uint amount)
diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
index 763eeb3c7c..3eb3ae1581 100644
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -174,9 +174,9 @@ static void DoPlaceMoreTrees(TileIndex tile)
 		int x = GB(r, 0, 5) - 16;
 		int y = GB(r, 8, 5) - 16;
 		uint dist = abs(x) + abs(y);
-		TileIndex cur_tile = TILE_MASK(tile + TileDiffXY(x, y));
+		TileIndex cur_tile = TileAddWrap(tile, x, y);
 
-		if (dist <= 13 && CanPlantTreesOnTile(cur_tile, true)) {
+		if (cur_tile != INVALID_TILE && dist <= 13 && CanPlantTreesOnTile(cur_tile, true)) {
 			PlaceTree(cur_tile, r);
 		}
 	}
@@ -212,7 +212,8 @@ static void PlaceTreeAtSameHeight(TileIndex tile, uint height)
 		uint32 r = Random();
 		int x = GB(r, 0, 5) - 16;
 		int y = GB(r, 8, 5) - 16;
-		TileIndex cur_tile = TILE_MASK(tile + TileDiffXY(x, y));
+		TileIndex cur_tile = TileAddWrap(tile, x, y);
+		if (cur_tile == INVALID_TILE) continue;
 
 		/* Keep in range of the existing tree */
 		if (abs(x) + abs(y) > 16) continue;
@@ -735,7 +736,7 @@ void OnTick_Trees()
 
 	/* place a tree at a random spot */
 	r = Random();
-	tile = TILE_MASK(r);
+	tile = RandomTileSeed(r);
 	if (CanPlantTreesOnTile(tile, false) && (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
 		PlantTreesOnTile(tile, tree, 0, 0);
 	}
diff --git a/src/unmovable_cmd.cpp b/src/unmovable_cmd.cpp
index 04be24e2d1..a3f5b5117a 100644
--- a/src/unmovable_cmd.cpp
+++ b/src/unmovable_cmd.cpp
@@ -452,10 +452,11 @@ void GenerateUnmovables()
 				MakeLighthouse(tile);
 				IncreaseGeneratingWorldProgress(GWP_UNMOVABLE);
 				lighthouses_to_build--;
-				assert(tile == TILE_MASK(tile));
+				TILE_ASSERT(tile);
 				break;
 			}
-			tile = TILE_MASK(tile + TileOffsByDiagDir(dir));
+			tile = AddTileIndexDiffCWrap(tile, TileIndexDiffCByDiagDir(dir));
+			if (tile == INVALID_TILE) break;
 		}
 	}
 }