diff --git a/capellambse_context_diagrams/collectors/default.py b/capellambse_context_diagrams/collectors/default.py
index 68609653..32a47771 100644
--- a/capellambse_context_diagrams/collectors/default.py
+++ b/capellambse_context_diagrams/collectors/default.py
@@ -60,14 +60,14 @@ def collector(
         "output": -makers.NEIGHBOR_VMARGIN,
     }
     child_boxes: list[_elkjs.ELKInputChild] = []
-    for i, local_ports, side in port_context_collector(ex_datas, ports):
-        _, label_height = helpers.get_text_extent(i.name)
+    for child, local_ports, side in port_context_collector(ex_datas, ports):
+        _, label_height = helpers.get_text_extent(child.name)
         height = max(
             label_height + 2 * makers.LABEL_VPAD,
             makers.PORT_PADDING
             + (makers.PORT_SIZE + makers.PORT_PADDING) * len(local_ports),
         )
-        if box := global_boxes.get(i.uuid):  # type: ignore[assignment]
+        if box := global_boxes.get(child.uuid):  # type: ignore[assignment]
             if box is centerbox:
                 continue
             box.setdefault("ports", []).extend(
@@ -76,23 +76,25 @@ def collector(
             box["height"] += height
         else:
             box = makers.make_box(
-                i, height=height, no_symbol=diagram.display_symbols_as_boxes
+                child,
+                height=height,
+                no_symbol=diagram.display_symbols_as_boxes,
             )
             box["ports"] = [makers.make_port(j.uuid) for j in local_ports]
-            if i.parent.uuid == centerbox["id"]:
+            if child.parent.uuid == centerbox["id"]:
                 child_boxes.append(box)
             else:
-                global_boxes[i.uuid] = box
+                global_boxes[child.uuid] = box
 
         if diagram.display_parent_relation:
-            if i == diagram.target.parent:
+            if child == diagram.target.parent:
                 _move_edge_to_local_edges(
                     box, connections, local_ports, diagram, data
                 )
-            elif i.parent == diagram.target.parent:
-                parent_box = global_boxes[i.parent.uuid]
+            elif child.parent == diagram.target.parent:
+                parent_box = global_boxes[child.parent.uuid]
                 parent_box.setdefault("children", []).append(
-                    global_boxes.pop(i.uuid)
+                    global_boxes.pop(child.uuid)
                 )
                 _move_edge_to_local_edges(
                     parent_box, connections, local_ports, diagram, data
diff --git a/capellambse_context_diagrams/serializers.py b/capellambse_context_diagrams/serializers.py
index a9f67460..259a5aa6 100644
--- a/capellambse_context_diagrams/serializers.py
+++ b/capellambse_context_diagrams/serializers.py
@@ -106,7 +106,7 @@ def deserialize_child(
             class type that stores all previously named classes.
         """
         styleclass: str | None = self.get_styleclass(child["id"])
-        element: diagram.Box | diagram.Edge
+        element: diagram.Box | diagram.Edge | diagram.Circle
         if child["type"] in {"node", "port"}:
             assert parent is None or isinstance(parent, diagram.Box)
             has_symbol_cls = False