diff --git a/src/landscape.cpp b/src/landscape.cpp
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -690,7 +690,7 @@ void ClearSnowLine()
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdLandscapeClear(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdLandscapeClear(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	CommandCost cost(EXPENSES_CONSTRUCTION);
 	bool do_clear = false;
@@ -740,7 +740,7 @@ CommandCost CmdLandscapeClear(TileIndex 
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdClearArea(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdClearArea(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	if (p1 >= MapSize()) return CMD_ERROR;