diff --git a/extensions/markdown-language-features/server/src/util/dispose.ts b/extensions/markdown-language-features/server/src/util/dispose.ts
index eee79003ae9..2e9d8dc6a14 100644
--- a/extensions/markdown-language-features/server/src/util/dispose.ts
+++ b/extensions/markdown-language-features/server/src/util/dispose.ts
@@ -3,14 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-export class MultiDisposeError extends Error {
-	constructor(
-		public readonly errors: any[]
-	) {
-		super(`Encountered errors while disposing of store. Errors: [${errors.join(', ')}]`);
-	}
-}
-
 export function disposeAll(disposables: Iterable<IDisposable>) {
 	const errors: any[] = [];
 
@@ -25,7 +17,7 @@ export function disposeAll(disposables: Iterable<IDisposable>) {
 	if (errors.length === 1) {
 		throw errors[0];
 	} else if (errors.length > 1) {
-		throw new MultiDisposeError(errors);
+		throw new AggregateError(errors, 'Encountered errors while disposing of store');
 	}
 }
 
@@ -60,21 +52,3 @@ export abstract class Disposable {
 	}
 }
 
-export class DisposableStore extends Disposable {
-	private readonly items = new Set<IDisposable>();
-
-	public override dispose() {
-		super.dispose();
-		disposeAll(this.items);
-		this.items.clear();
-	}
-
-	public add<T extends IDisposable>(item: T): T {
-		if (this.isDisposed) {
-			console.warn('Adding to disposed store. Item will be leaked');
-		}
-
-		this.items.add(item);
-		return item;
-	}
-}
diff --git a/extensions/markdown-language-features/src/util/dispose.ts b/extensions/markdown-language-features/src/util/dispose.ts
index ca78e4a821b..483fab30638 100644
--- a/extensions/markdown-language-features/src/util/dispose.ts
+++ b/extensions/markdown-language-features/src/util/dispose.ts
@@ -5,14 +5,6 @@
 
 import * as vscode from 'vscode';
 
-export class MultiDisposeError extends Error {
-	constructor(
-		public readonly errors: any[]
-	) {
-		super(`Encountered errors while disposing of store. Errors: [${errors.join(', ')}]`);
-	}
-}
-
 export function disposeAll(disposables: Iterable<vscode.Disposable>) {
 	const errors: any[] = [];
 
@@ -27,7 +19,7 @@ export function disposeAll(disposables: Iterable<vscode.Disposable>) {
 	if (errors.length === 1) {
 		throw errors[0];
 	} else if (errors.length > 1) {
-		throw new MultiDisposeError(errors);
+		throw new AggregateError(errors, 'Encountered errors while disposing of store');
 	}
 }
 
diff --git a/extensions/tsconfig.base.json b/extensions/tsconfig.base.json
index 5651d572632..2e4a6009a02 100644
--- a/extensions/tsconfig.base.json
+++ b/extensions/tsconfig.base.json
@@ -20,7 +20,10 @@
 			"ES2020.Promise",
 			"ES2020.String",
 			"ES2020.Symbol.WellKnown",
-			"ES2020.Intl"
+			"ES2020.Intl",
+			"ES2021.Promise",
+			"ES2021.String",
+			"ES2021.WeakRef"
 		],
 		"module": "commonjs",
 		"strict": true,