diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -525,7 +525,7 @@ CommandCost CmdBuildTunnel(TileIndex sta
 	DiagDirection direction = GetInclinedSlopeDirection(start_tileh);
 	if (direction == INVALID_DIAGDIR) return_cmd_error(STR_ERROR_SITE_UNSUITABLE_FOR_TUNNEL);
 
-	if (IsWaterTile(start_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
+	if (HasTileWaterGround(start_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
 
 	CommandCost ret = DoCommand(start_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 	if (ret.Failed()) return ret;
@@ -582,7 +582,7 @@ CommandCost CmdBuildTunnel(TileIndex sta
 	/* if the command fails from here on we want the end tile to be highlighted */
 	_build_tunnel_endtile = end_tile;
 
-	if (IsWaterTile(end_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
+	if (HasTileWaterGround(end_tile)) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
 
 	/* Clear the tile in any case */
 	ret = DoCommand(end_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);