diff --git a/src/c3nav/mapdata/models/geometry/space.py b/src/c3nav/mapdata/models/geometry/space.py
index c5cac761..695b459a 100644
--- a/src/c3nav/mapdata/models/geometry/space.py
+++ b/src/c3nav/mapdata/models/geometry/space.py
@@ -169,6 +169,7 @@ class Ramp(SpaceGeometryMixin, models.Model):
         default_related_name = 'ramps'
 
 
+# todo: move to other file? this is NOT a geometry!
 class ObstacleGroup(TitledMixin, models.Model):
     color = models.CharField(max_length=32, null=True, blank=True)
     in_legend = models.BooleanField(default=False, verbose_name=_('show in legend (if color set)'))