diff --git a/src/c3nav/mapdata/views.py b/src/c3nav/mapdata/views.py
index 8d123f53..5c8be822 100644
--- a/src/c3nav/mapdata/views.py
+++ b/src/c3nav/mapdata/views.py
@@ -98,7 +98,7 @@ def history(request, level, mode, format):
         raise PermissionDenied
     level = get_object_or_404(Level, pk=level)
 
-    if mode == 'render' and level.on_top_of_id is None:
+    if mode == 'render' and level.on_top_of_id is not None:
         raise Http404
 
     history = MapHistory.open_level(level.pk, mode)