Index: src/terraform_cmd.cpp
===================================================================
--- src/terraform_cmd.cpp	(revision 13025)
+++ src/terraform_cmd.cpp	(working copy)
@@ -301,7 +301,10 @@
 				return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
 			}
 			/* Check tiletype-specific things, and add extra-cost */
+			const bool curr_gen = _generating_world;
+			if (_game_mode == GM_EDITOR) _generating_world = true; // used to create green terraformed land
 			CommandCost cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, flags | DC_AUTO, z_min * TILE_HEIGHT, tileh);
+			_generating_world = curr_gen;
 			if (CmdFailed(cost)) {
 				_terraform_err_tile = tile;
 				return cost;
Index: src/terraform_gui.cpp
===================================================================
--- src/terraform_gui.cpp	(revision 13025)
+++ src/terraform_gui.cpp	(working copy)
@@ -339,8 +339,6 @@
 	int sizex, sizey;
 	uint h;
 
-	_generating_world = true; // used to create green terraformed land
-
 	if (_terraform_size == 1) {
 		StringID msg =
 			mode ? STR_0808_CAN_T_RAISE_LAND_HERE : STR_0809_CAN_T_LOWER_LAND_HERE;
@@ -376,8 +374,6 @@
 			}
 		} END_TILE_LOOP(tile2, sizex, sizey, tile)
 	}
-
-	_generating_world = false;
 }
 
 static void PlaceProc_RaiseBigLand(TileIndex tile)