diff --git a/packages/base/src/widget.ts b/packages/base/src/widget.ts
index 174698b856..74a6c9a724 100644
--- a/packages/base/src/widget.ts
+++ b/packages/base/src/widget.ts
@@ -563,7 +563,8 @@ export class WidgetModel extends Backbone.Model {
    */
   serialize(state: Dict<any>): JSONObject {
     const serializers =
-      (this.constructor as typeof WidgetModel).serializers || JSONExt.emptyObject;
+      (this.constructor as typeof WidgetModel).serializers ||
+      JSONExt.emptyObject;
     for (const k of Object.keys(state)) {
       try {
         const keySerializers = serializers[k] || JSONExt.emptyObject;