diff --git a/src/misc.cpp b/src/misc.cpp
index 12ba724342..cdd48c293c 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -70,6 +70,7 @@ void InitializeGame(uint size_x, uint size_y, bool reset_date)
 	_realtime_tick = 0;
 	_date_fract = 0;
 	_cur_tileloop_tile = 0;
+	_thd.redsq = INVALID_TILE;
 	MakeNewgameSettingsLive();
 
 	if (reset_date) {
diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index 81a67b1921..bc588a447a 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -505,7 +505,7 @@ public:
 
 	~ErrmsgWindow()
 	{
-		SetRedErrorSquare(0);
+		SetRedErrorSquare(INVALID_TILE);
 		extern StringID _switch_mode_errorstr;
 		_switch_mode_errorstr = INVALID_STRING_ID;
 	}
diff --git a/src/terraform_cmd.cpp b/src/terraform_cmd.cpp
index aa79ac9938..25c193299c 100644
--- a/src/terraform_cmd.cpp
+++ b/src/terraform_cmd.cpp
@@ -165,10 +165,9 @@ static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int
 	if ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1)) {
 		/*
 		 * Determine a sensible error tile
-		 * Note: If x and y are both zero this will disable the error tile. (Tile 0 cannot be highlighted :( )
 		 */
-		if ((x == 1) && (y != 0)) x = 0;
-		if ((y == 1) && (x != 0)) y = 0;
+		if (x == 1) x = 0;
+		if (y == 1) y = 0;
 		_terraform_err_tile = TileXY(x, y);
 		return_cmd_error(STR_0002_TOO_CLOSE_TO_EDGE_OF_MAP);
 	}
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 9eeb08f2bb..d507772b43 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -878,7 +878,7 @@ static void DrawAutorailSelection(const TileInfo *ti, uint autorail_type)
 static void DrawTileSelection(const TileInfo *ti)
 {
 	/* Draw a red error square? */
-	bool is_redsq = _thd.redsq != 0 && _thd.redsq == ti->tile;
+	bool is_redsq = _thd.redsq == ti->tile;
 	if (is_redsq) DrawTileSelectionRect(ti, PALETTE_TILE_RED_PULSATING);
 
 	/* no selection active? */
@@ -2085,8 +2085,8 @@ void SetRedErrorSquare(TileIndex tile)
 	_thd.redsq = tile;
 
 	if (tile != old) {
-		if (tile != 0) MarkTileDirtyByTile(tile);
-		if (old  != 0) MarkTileDirtyByTile(old);
+		if (tile != INVALID_TILE) MarkTileDirtyByTile(tile);
+		if (old  != INVALID_TILE) MarkTileDirtyByTile(old);
 	}
 }