--- a/buses.py	Wed Jun 28 17:51:40 2017 +0300
+++ b/buses.py	Wed Jun 28 17:52:42 2017 +0300
@@ -308,6 +308,7 @@
 		bus_stops_by_name = dict(bus_stops_by_name)
 
 		# ryhmittele bus_stops nimen mukaan
+		global all_clusters
 		all_clusters = []
 		def cluster_bus_stops():
 			sorted_bus_stops = sorted(bus_stops.values(), key = lambda bus_stop: bus_stop.name)