diff --git a/boxes/generators/organpipe.py b/boxes/generators/organpipe.py
index 22d21ad..43bb636 100644
--- a/boxes/generators/organpipe.py
+++ b/boxes/generators/organpipe.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # Copyright (C) 2013-2018 Florian Festi
 #
 # Based on pipecalc by Christian F. Coors