diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -257,7 +257,7 @@ static Money TunnelBridgeClearCost(TileI
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdBuildBridge(TileIndex end_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdBuildBridge(TileIndex end_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	CompanyID company = _current_company;
 
@@ -630,7 +630,7 @@ CommandCost CmdBuildBridge(TileIndex end
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	CompanyID company = _current_company;