diff --git a/review/api/widgets.api.md b/review/api/widgets.api.md
index 20010fbf3..c11eab012 100644
--- a/review/api/widgets.api.md
+++ b/review/api/widgets.api.md
@@ -56,6 +56,7 @@ export class AccordionPanel extends SplitPanel {
     addWidget(widget: Widget): void;
     collapse(index: number): void;
     expand(index: number): void;
+    get expansionToggled(): ISignal<this, number>;
     handleEvent(event: Event): void;
     insertWidget(index: number, widget: Widget): void;
     protected onAfterDetach(msg: Message): void;