1 files changed, 5 insertions, 1 deletions
diff --git a/src/new_fields/List.ts b/src/new_fields/List.ts
index ec1bf44a9..c1bd15cd1 100644
--- a/src/new_fields/List.ts
+++ b/src/new_fields/List.ts
@@ -3,7 +3,7 @@ import { Field, Update, Self } from "./Doc";
 import { setter, getter, deleteProperty } from "./util";
 import { serializable, alias, list } from "serializr";
 import { observable, observe, IArrayChange, IArraySplice, IObservableArray, Lambda, reaction } from "mobx";
-import { ObjectField, OnUpdate } from "./ObjectField";
+import { ObjectField, OnUpdate, Copy } from "./ObjectField";
 import { RefField } from "./RefField";
 import { ProxyField } from "./Proxy";
 
@@ -215,6 +215,10 @@ class ListImpl<T extends Field> extends ObjectField {
         this.___fields = value;
     }
 
+    [Copy]() {
+        return new ListImpl<T>();
+    }
+
     // @serializable(alias("fields", list(autoObject())))
     @observable
     private ___fields: (T | null | undefined)[];