diff --git a/src/openklant/components/utils/schema.py b/src/openklant/components/utils/schema.py
index 1d66de4d..b7972366 100644
--- a/src/openklant/components/utils/schema.py
+++ b/src/openklant/components/utils/schema.py
@@ -55,7 +55,12 @@ def get_expand_response(self, serializer, base_response, direction):
 
             inclusion_ref = self.resolve_serializer(inclusion_serializer, direction).ref
 
-            many = True if hasattr(inclusion_field, "child_relation") else False
+            many = (
+                True
+                if hasattr(inclusion_field, "child_relation")
+                or hasattr(inclusion_field, "many")
+                else False
+            )
             if many:
                 inclusion_schema = append_meta(build_array_type(inclusion_ref), meta)
             else: