diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -378,7 +378,7 @@ void GenerateTrees()
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	StringID msg = INVALID_STRING_ID;
 	CommandCost cost(EXPENSES_OTHER);