diff --git a/openmc/geometry.py b/openmc/geometry.py
index 8227b1053..3a2c18311 100644
--- a/openmc/geometry.py
+++ b/openmc/geometry.py
@@ -167,6 +167,7 @@ class Geometry(object):
             outer = get(elem, 'outer')
             if outer is not None:
                 lat.outer = get_universe(int(outer))
+                child_of[lat.outer].append(lat)
             universes[lat_id] = lat
 
             # Get array of universes
@@ -188,6 +189,7 @@ class Geometry(object):
             outer = get(elem, 'outer')
             if outer is not None:
                 lat.outer = get_universe(int(outer))
+                child_of[lat.outer].append(lat)
             universes[lat_id] = lat
 
             # Get nested lists of universes