diff --git a/combo_plugin_gnm/templatetags/gnm.py b/combo_plugin_gnm/templatetags/gnm.py
index e9aceff..d462009 100644
--- a/combo_plugin_gnm/templatetags/gnm.py
+++ b/combo_plugin_gnm/templatetags/gnm.py
@@ -721,7 +721,7 @@ def get_goto_cell(page, request):
 
 @register.assignment_tag
 def get_collectivity_slugs():
-    return settings.COLLECTIVITY_LABELS.keys()
+    return list(settings.COLLECTIVITY_LABELS.keys())
 
 @register.filter
 def indice_values(indices):