diff --git a/extensions/html-language-features/client/src/customData.ts b/extensions/html-language-features/client/src/customData.ts
index 146fef2f3ee..02c5b0d0a7d 100644
--- a/extensions/html-language-features/client/src/customData.ts
+++ b/extensions/html-language-features/client/src/customData.ts
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { workspace, extensions, Uri, EventEmitter, Disposable } from 'vscode';
-import { resolvePath, joinPath, uriScheme } from './requests';
+import { resolvePath, joinPath } from './requests';
 
 
 export function getCustomDataSource(toDispose: Disposable[]) {
@@ -44,6 +44,10 @@ export function getCustomDataSource(toDispose: Disposable[]) {
 	};
 }
 
+function isURI(uriOrPath: string) {
+	return /^(?<scheme>\w[\w\d+.-]*):/.test(uriOrPath);
+}
+
 
 function getCustomDataPathsInAllWorkspaces(): Set<string> {
 	const workspaceFolders = workspace.workspaceFolders;
@@ -54,16 +58,16 @@ function getCustomDataPathsInAllWorkspaces(): Set<string> {
 		return dataPaths;
 	}
 
-	const collect = (paths: string[] | undefined, rootFolder: Uri) => {
-		if (Array.isArray(paths)) {
-			for (const path of paths) {
-				if (typeof path === 'string') {
-					if (!uriScheme.test(path)) {
-						// only resolve file paths relative to extension
-						dataPaths.add(resolvePath(rootFolder, path).toString());
+	const collect = (uriOrPaths: string[] | undefined, rootFolder: Uri) => {
+		if (Array.isArray(uriOrPaths)) {
+			for (const uriOrPath of uriOrPaths) {
+				if (typeof uriOrPath === 'string') {
+					if (!isURI(uriOrPath)) {
+						// path in the workspace
+						dataPaths.add(resolvePath(rootFolder, uriOrPath).toString());
 					} else {
-						// others schemes
-						dataPaths.add(path);
+						// external uri
+						dataPaths.add(uriOrPath);
 					}
 				}
 			}
@@ -93,13 +97,13 @@ function getCustomDataPathsFromAllExtensions(): Set<string> {
 	for (const extension of extensions.all) {
 		const customData = extension.packageJSON?.contributes?.html?.customData;
 		if (Array.isArray(customData)) {
-			for (const rp of customData) {
-				if (!uriScheme.test(rp)) {
-					// no schame -> resolve relative to extension
-					dataPaths.add(joinPath(extension.extensionUri, rp).toString());
+			for (const uriOrPath of customData) {
+				if (!isURI(uriOrPath)) {
+					// relative path in an extension
+					dataPaths.add(joinPath(extension.extensionUri, uriOrPath).toString());
 				} else {
-					// actual schemes
-					dataPaths.add(rp);
+					// external uri
+					dataPaths.add(uriOrPath);
 				}
 
 			}
diff --git a/extensions/html-language-features/client/src/htmlClient.ts b/extensions/html-language-features/client/src/htmlClient.ts
index 3e7ca38be7e..bfb241c2250 100644
--- a/extensions/html-language-features/client/src/htmlClient.ts
+++ b/extensions/html-language-features/client/src/htmlClient.ts
@@ -120,7 +120,7 @@ export function startClient(context: ExtensionContext, newLanguageClient: Langua
 	toDispose.push(disposable);
 	client.onReady().then(() => {
 
-		serveFileSystemRequests(client, runtime, context.subscriptions);
+		toDispose.push(serveFileSystemRequests(client, runtime));
 
 		client.sendNotification(CustomDataChangedNotification.type, customDataSource.uris);
 		customDataSource.onDidChange(() => {
diff --git a/extensions/html-language-features/client/src/requests.ts b/extensions/html-language-features/client/src/requests.ts
index aa75e6b615f..867ad6fc7d4 100644
--- a/extensions/html-language-features/client/src/requests.ts
+++ b/extensions/html-language-features/client/src/requests.ts
@@ -3,12 +3,10 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { Uri, workspace } from 'vscode';
+import { Uri, workspace, Disposable } from 'vscode';
 import { RequestType, CommonLanguageClient } from 'vscode-languageclient';
 import { Runtime } from './htmlClient';
 
-export const uriScheme = /^(?<scheme>\w[\w\d+.-]*):/;
-
 export namespace FsContentRequest {
 	export const type: RequestType<{ uri: string; encoding?: string; }, string, any> = new RequestType('fs/content');
 }
@@ -20,37 +18,32 @@ export namespace FsReadDirRequest {
 	export const type: RequestType<string, [string, FileType][], any> = new RequestType('fs/readDir');
 }
 
-export function serveFileSystemRequests(client: CommonLanguageClient, runtime: Runtime, subscriptions: { dispose(): any }[]) {
-	subscriptions.push(client.onRequest(FsContentRequest.type, (param: { uri: string; encoding?: string; }) => {
-		const uri = param.uri.match(uriScheme);
-		if (uri?.groups?.scheme === 'file') {
-			if (runtime.fs) {
-				return runtime.fs.getContent(param.uri);
-			} else {
-				return workspace.fs.readFile(Uri.parse(param.uri)).then(buffer => {
-					return new runtime.TextDecoder(param.encoding).decode(buffer);
-				});
-			}
-		} else {
-			return workspace.openTextDocument(Uri.parse(param.uri)).then(doc => {
-				return doc.getText();
-			});
+export function serveFileSystemRequests(client: CommonLanguageClient, runtime: Runtime): Disposable {
+	const disposables = [];
+	disposables.push(client.onRequest(FsContentRequest.type, (param: { uri: string; encoding?: string; }) => {
+		const uri = Uri.parse(param.uri);
+		if (uri.scheme === 'file' && runtime.fs) {
+			return runtime.fs.getContent(param.uri);
 		}
+		return workspace.fs.readFile(uri).then(buffer => {
+			return new runtime.TextDecoder(param.encoding).decode(buffer);
+		});
 	}));
-	subscriptions.push(client.onRequest(FsReadDirRequest.type, (uriString: string) => {
-		const uri = uriString.match(uriScheme);
-		if (uri?.groups?.scheme === 'file' && runtime.fs) {
+	disposables.push(client.onRequest(FsReadDirRequest.type, (uriString: string) => {
+		const uri = Uri.parse(uriString);
+		if (uri.scheme === 'file' && runtime.fs) {
 			return runtime.fs.readDirectory(uriString);
 		}
-		return workspace.fs.readDirectory(Uri.parse(uriString));
+		return workspace.fs.readDirectory(uri);
 	}));
-	subscriptions.push(client.onRequest(FsStatRequest.type, (uriString: string) => {
-		const uri = uriString.match(uriScheme);
-		if (uri?.groups?.scheme === 'file' && runtime.fs) {
+	disposables.push(client.onRequest(FsStatRequest.type, (uriString: string) => {
+		const uri = Uri.parse(uriString);
+		if (uri.scheme === 'file' && runtime.fs) {
 			return runtime.fs.stat(uriString);
 		}
-		return workspace.fs.stat(Uri.parse(uriString));
+		return workspace.fs.stat(uri);
 	}));
+	return Disposable.from(...disposables);
 }
 
 export enum FileType {