diff --git a/src/vs/base/browser/ui/list/listWidget.ts b/src/vs/base/browser/ui/list/listWidget.ts
index 1ed888d7f2a..0e3598aa839 100644
--- a/src/vs/base/browser/ui/list/listWidget.ts
+++ b/src/vs/base/browser/ui/list/listWidget.ts
@@ -656,7 +656,10 @@ export class List<T> implements ISpliceable<T>, IDisposable {
 	}
 
 	splice(start: number, deleteCount: number, elements: T[] = []): void {
-		this.eventBufferer.bufferEvents(() => this.spliceable.splice(start, deleteCount, elements));
+		this.eventBufferer.bufferEvents(() => {
+			this.spliceable.splice(start, deleteCount, elements);
+			this.view.domNode.setAttribute('aria-setsize', this.length.toString());
+		});
 	}
 
 	get length(): number {
@@ -712,6 +715,7 @@ export class List<T> implements ISpliceable<T>, IDisposable {
 	setFocus(indexes: number[]): void {
 		indexes = indexes.sort(numericSort);
 		this.focus.set(indexes);
+		this.view.domNode.setAttribute('aria-posinset', indexes.length ? (indexes[0] + 1).toString() : undefined);
 	}
 
 	focusNext(n = 1, loop = false): void {