diff --git a/src/road.cpp b/src/road.cpp
index 119b567f5d..c2315f03e1 100644
--- a/src/road.cpp
+++ b/src/road.cpp
@@ -382,12 +382,13 @@ static TileIndex BuildTunnel(PathNode *current, TileIndex end_tile = INVALID_TIL
 		const TileIndexDiff delta = TileOffsByDiagDir(direction);
 		end_tile = start_tile;
 		int end_z;
+		const uint tunnel_length_limit = std::min<uint>(_settings_game.construction.max_tunnel_length, 30);
 
 		for (int tunnel_length = 1;;tunnel_length++) {
 			end_tile += delta;
 
 			if (!IsValidTile(end_tile)) return INVALID_TILE;
-			if (tunnel_length > _settings_game.construction.max_tunnel_length) return INVALID_TILE;
+			if (tunnel_length > tunnel_length_limit) return INVALID_TILE;
 
 			GetTileSlope(end_tile, &end_z);