diff --git a/ckanext/datastore/backend/postgres.py b/ckanext/datastore/backend/postgres.py
index fd4c333751a..ee27e0ab89f 100644
--- a/ckanext/datastore/backend/postgres.py
+++ b/ckanext/datastore/backend/postgres.py
@@ -284,7 +284,10 @@ def _cache_types(context):
             # redo cache types with json now available.
             return _cache_types(context)
 
-        register_composite('nested', connection.connection, True)
+        try:
+            register_composite('nested', connection.connection.connection, True)
+        except AttributeError:
+            register_composite('nested', connection.connection, True)
 
 
 def _pg_version_is_at_least(connection, version):