1 files changed, 1 insertions, 1 deletions
diff --git a/src/new_fields/ObjectField.ts b/src/new_fields/ObjectField.ts
index 0f3777af6..715c6a924 100644
--- a/src/new_fields/ObjectField.ts
+++ b/src/new_fields/ObjectField.ts
@@ -5,7 +5,7 @@ export const Parent = Symbol("Parent");
 export const Copy = Symbol("Copy");
 
 export abstract class ObjectField {
-    protected [OnUpdate]?: (diff?: any) => void;
+    protected [OnUpdate](diff?: any) { };
     private [Parent]?: Doc;
     abstract [Copy](): ObjectField;
 }