diff --git a/build/lib/extensions.js b/build/lib/extensions.js
index 202cded3dcc..bc715ea3baa 100644
--- a/build/lib/extensions.js
+++ b/build/lib/extensions.js
@@ -44,11 +44,20 @@ function fromLocal(extensionPath, sourceMappingURLBase) {
             contents: fs.createReadStream(filePath)
         }); });
         var filesStream = es.readArray(files);
-        // check for a webpack configuration file, then invoke webpack
+        // check for a webpack configuration files, then invoke webpack
         // and merge its output with the files stream. also rewrite the package.json
         // file to a new entry point
-        if (fs.existsSync(path.join(extensionPath, 'extension.webpack.config.js'))) {
-            var packageJsonFilter = filter('package.json', { restore: true });
+        var pattern = path.join(extensionPath, '/**/extension.webpack.config.js');
+        var webpackConfigLocations = glob.sync(pattern, { ignore: ['**/node_modules'] });
+        if (webpackConfigLocations.length) {
+            var packageJsonFilter = filter(function (f) {
+                if (path.basename(f.path) === 'package.json') {
+                    // only modify package.json's next to the webpack file.
+                    // to be safe, use existsSync instead of path comparison.
+                    return fs.existsSync(path.join(path.dirname(f.path), 'extension.webpack.config.js'));
+                }
+                return false;
+            }, { restore: true });
             var patchFilesStream = filesStream
                 .pipe(packageJsonFilter)
                 .pipe(buffer())
@@ -58,38 +67,36 @@ function fromLocal(extensionPath, sourceMappingURLBase) {
                 return data;
             }))
                 .pipe(packageJsonFilter.restore);
-            var webpackConfig = __assign({}, require(path.join(extensionPath, 'extension.webpack.config.js')), { mode: 'production', stats: 'errors-only' });
-            var webpackStream = webpackGulp(webpackConfig, webpack)
-                .pipe(es.through(function (data) {
-                data.stat = data.stat || {};
-                data.base = extensionPath;
-                this.emit('data', data);
-            }))
-                .pipe(es.through(function (data) {
-                // source map handling:
-                // * rewrite sourceMappingURL
-                // * save to disk so that upload-task picks this up
-                if (sourceMappingURLBase) {
-                    var contents = data.contents.toString('utf8');
-                    data.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, function (_m, g1) {
-                        return "\n//# sourceMappingURL=" + sourceMappingURLBase + "/extensions/" + path.basename(extensionPath) + "/dist/" + g1;
-                    }), 'utf8');
-                    if (/\.js\.map$/.test(data.path)) {
-                        if (!fs.existsSync(path.dirname(data.path))) {
-                            fs.mkdirSync(path.dirname(data.path));
+            var webpackStreams = webpackConfigLocations.map(function (webpackConfigPath) {
+                var webpackConfig = __assign({}, require(webpackConfigPath), { mode: 'production', stats: 'errors-only' });
+                var relativeOutputPath = path.relative(extensionPath, webpackConfig.output.path);
+                var webpackBaseDir = path.dirname(webpackConfigPath);
+                return webpackGulp(webpackConfig, webpack)
+                    .pipe(es.through(function (data) {
+                    data.stat = data.stat || {};
+                    data.base = extensionPath;
+                    this.emit('data', data);
+                }))
+                    .pipe(es.through(function (data) {
+                    // source map handling:
+                    // * rewrite sourceMappingURL
+                    // * save to disk so that upload-task picks this up
+                    if (sourceMappingURLBase) {
+                        var contents = data.contents.toString('utf8');
+                        data.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, function (_m, g1) {
+                            return "\n//# sourceMappingURL=" + sourceMappingURLBase + "/extensions/" + path.basename(extensionPath) + "/" + relativeOutputPath + "/" + g1;
+                        }), 'utf8');
+                        if (/\.js\.map$/.test(data.path)) {
+                            if (!fs.existsSync(path.dirname(data.path))) {
+                                fs.mkdirSync(path.dirname(data.path));
+                            }
+                            fs.writeFileSync(data.path, data.contents);
                         }
-                        fs.writeFileSync(data.path, data.contents);
                     }
-                }
-                this.emit('data', data);
-            }));
-            es.merge(webpackStream, patchFilesStream)
-                // .pipe(es.through(function (data) {
-                // 	// debug
-                // 	console.log('out', data.path, data.contents.length);
-                // 	this.emit('data', data);
-                // }))
-                .pipe(result);
+                    this.emit('data', data);
+                }));
+            });
+            es.merge.apply(es, webpackStreams.concat([patchFilesStream])).pipe(result);
         }
         else {
             filesStream.pipe(result);
diff --git a/build/lib/extensions.ts b/build/lib/extensions.ts
index 3c74455ccad..dec4c00bd36 100644
--- a/build/lib/extensions.ts
+++ b/build/lib/extensions.ts
@@ -41,11 +41,21 @@ export function fromLocal(extensionPath: string, sourceMappingURLBase?: string):
 
 		const filesStream = es.readArray(files);
 
-		// check for a webpack configuration file, then invoke webpack
+		// check for a webpack configuration files, then invoke webpack
 		// and merge its output with the files stream. also rewrite the package.json
 		// file to a new entry point
-		if (fs.existsSync(path.join(extensionPath, 'extension.webpack.config.js'))) {
-			const packageJsonFilter = filter('package.json', { restore: true });
+		const pattern = path.join(extensionPath, '/**/extension.webpack.config.js');
+		const webpackConfigLocations = (<string[]>glob.sync(pattern, { ignore: ['**/node_modules'] }));
+		if (webpackConfigLocations.length) {
+
+			const packageJsonFilter = filter(f => {
+				if (path.basename(f.path) === 'package.json') {
+					// only modify package.json's next to the webpack file.
+					// to be safe, use existsSync instead of path comparison.
+					return fs.existsSync(path.join(path.dirname(f.path), 'extension.webpack.config.js'));
+				}
+				return false;
+			}, { restore: true });
 
 			const patchFilesStream = filesStream
 				.pipe(packageJsonFilter)
@@ -57,38 +67,42 @@ export function fromLocal(extensionPath: string, sourceMappingURLBase?: string):
 				}))
 				.pipe(packageJsonFilter.restore);
 
-			const webpackConfig = {
-				...require(path.join(extensionPath, 'extension.webpack.config.js')),
-				...{ mode: 'production', stats: 'errors-only' }
-			};
-			const webpackStream = webpackGulp(webpackConfig, webpack)
-				.pipe(es.through(function (data) {
-					data.stat = data.stat || {};
-					data.base = extensionPath;
-					this.emit('data', data);
-				}))
-				.pipe(es.through(function (data: File) {
-					// source map handling:
-					// * rewrite sourceMappingURL
-					// * save to disk so that upload-task picks this up
-					if (sourceMappingURLBase) {
-						const contents = (<Buffer>data.contents).toString('utf8');
-						data.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, function (_m, g1) {
-							return `\n//# sourceMappingURL=${sourceMappingURLBase}/extensions/${path.basename(extensionPath)}/dist/${g1}`;
-						}), 'utf8');
+			const webpackStreams = webpackConfigLocations.map(webpackConfigPath => {
+				const webpackConfig = {
+					...require(webpackConfigPath),
+					...{ mode: 'production', stats: 'errors-only' }
+				};
+				let relativeOutputPath = path.relative(extensionPath, webpackConfig.output.path);
+				let webpackBaseDir = path.dirname(webpackConfigPath);
 
-						if (/\.js\.map$/.test(data.path)) {
-							if (!fs.existsSync(path.dirname(data.path))) {
-								fs.mkdirSync(path.dirname(data.path));
+				return webpackGulp(webpackConfig, webpack)
+					.pipe(es.through(function (data) {
+						data.stat = data.stat || {};
+						data.base = extensionPath;
+						this.emit('data', data);
+					}))
+					.pipe(es.through(function (data: File) {
+						// source map handling:
+						// * rewrite sourceMappingURL
+						// * save to disk so that upload-task picks this up
+						if (sourceMappingURLBase) {
+							const contents = (<Buffer>data.contents).toString('utf8');
+							data.contents = Buffer.from(contents.replace(/\n\/\/# sourceMappingURL=(.*)$/gm, function (_m, g1) {
+								return `\n//# sourceMappingURL=${sourceMappingURLBase}/extensions/${path.basename(extensionPath)}/${relativeOutputPath}/${g1}`;
+							}), 'utf8');
+
+							if (/\.js\.map$/.test(data.path)) {
+								if (!fs.existsSync(path.dirname(data.path))) {
+									fs.mkdirSync(path.dirname(data.path));
+								}
+								fs.writeFileSync(data.path, data.contents);
 							}
-							fs.writeFileSync(data.path, data.contents);
 						}
-					}
-					this.emit('data', data);
-				}))
-				;
+						this.emit('data', data);
+					}));
+			});
 
-			es.merge(webpackStream, patchFilesStream)
+			es.merge(...webpackStreams, patchFilesStream)
 				// .pipe(es.through(function (data) {
 				// 	// debug
 				// 	console.log('out', data.path, data.contents.length);
diff --git a/extensions/css-language-features/.vscodeignore b/extensions/css-language-features/.vscodeignore
index debeb96e691..89a62ee0761 100644
--- a/extensions/css-language-features/.vscodeignore
+++ b/extensions/css-language-features/.vscodeignore
@@ -1,11 +1,21 @@
 test/**
 .vscode/**
-client/src/**
-client/tsconfig.json
-server/src/**
-server/test/**
-server/out/test/**
 server/.vscode/**
+node_modules/**
+server/node_modules/**
+client/src/**
+server/src/**
+client/out/**
+server/out/**
+client/tsconfig.json
 server/tsconfig.json
-**/node_modules/@types/**
-**/node_modules/*/lib/esm/**
\ No newline at end of file
+server/test/**
+server/bin/**
+server/build/**
+server/yarn.lock
+server/.npmignore
+yarn.lock
+server/extension.webpack.config.js
+extension.webpack.config.js
+!node_modules/vscode-nls/**
+!server/node_modules/vscode-nls/**
\ No newline at end of file
diff --git a/extensions/css-language-features/client/src/cssMain.ts b/extensions/css-language-features/client/src/cssMain.ts
index dce55982cb9..e91d5408054 100644
--- a/extensions/css-language-features/client/src/cssMain.ts
+++ b/extensions/css-language-features/client/src/cssMain.ts
@@ -4,6 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 'use strict';
 import * as path from 'path';
+import * as fs from 'fs';
 
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
@@ -14,8 +15,9 @@ import { LanguageClient, LanguageClientOptions, ServerOptions, TransportKind, Di
 // this method is called when vs code is activated
 export function activate(context: ExtensionContext) {
 
-	// The server is implemented in node
-	let serverModule = context.asAbsolutePath(path.join('server', 'out', 'cssServerMain.js'));
+	let serverMain = readJSONFile(context.asAbsolutePath('./server/package.json')).main;
+	let serverModule = context.asAbsolutePath(path.join('server', serverMain));
+
 	// The debug options for the server
 	let debugOptions = { execArgv: ['--nolazy', '--inspect=6044'] };
 
@@ -120,3 +122,12 @@ export function activate(context: ExtensionContext) {
 	}
 }
 
+function readJSONFile(location: string) {
+	try {
+		return JSON.parse(fs.readFileSync(location).toString());
+	} catch (e) {
+		console.log(`Problems reading ${location}: ${e}`);
+		return {};
+	}
+}
+
diff --git a/extensions/css-language-features/extension.webpack.config.js b/extensions/css-language-features/extension.webpack.config.js
new file mode 100644
index 00000000000..593d1340b7f
--- /dev/null
+++ b/extensions/css-language-features/extension.webpack.config.js
@@ -0,0 +1,40 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../shared.webpack.config');
+const CopyWebpackPlugin = require('copy-webpack-plugin');
+const path = require('path');
+
+module.exports = withDefaults({
+	context: path.join(__dirname, 'client'),
+	entry: {
+		extension: './src/cssMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'cssMain.js',
+		path: path.join(__dirname, 'client', 'dist'),
+		libraryTarget: "commonjs",
+	},
+	externals: {
+		'./files': 'commonjs', // ignored because it doesn't exist
+	},
+	plugins: [
+		new CopyWebpackPlugin([
+			{ from: './out/*.sh', to: '[name].sh' },
+			{ from: './out/nls.*.json', to: '[name].json' }
+		])
+	]
+});
diff --git a/extensions/css-language-features/package.json b/extensions/css-language-features/package.json
index cf0903f0a81..ade358261dc 100644
--- a/extensions/css-language-features/package.json
+++ b/extensions/css-language-features/package.json
@@ -708,7 +708,7 @@
     ]
   },
   "dependencies": {
-    "vscode-languageclient": "^4.4.0",
+    "vscode-languageclient": "^5.1.0-next.4",
     "vscode-nls": "^3.2.4"
   },
   "devDependencies": {
diff --git a/extensions/css-language-features/server/build/filesFillIn.js b/extensions/css-language-features/server/build/filesFillIn.js
new file mode 100644
index 00000000000..906617384e0
--- /dev/null
+++ b/extensions/css-language-features/server/build/filesFillIn.js
@@ -0,0 +1,5 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+module.exports = {};
\ No newline at end of file
diff --git a/extensions/css-language-features/server/extension.webpack.config.js b/extensions/css-language-features/server/extension.webpack.config.js
new file mode 100644
index 00000000000..f89cb636f38
--- /dev/null
+++ b/extensions/css-language-features/server/extension.webpack.config.js
@@ -0,0 +1,38 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../../shared.webpack.config');
+const path = require('path');
+var webpack = require('webpack');
+
+module.exports = withDefaults({
+	context: path.join(__dirname),
+	entry: {
+		extension: './src/cssServerMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'cssServerMain.js',
+		path: path.join(__dirname, 'dist'),
+		libraryTarget: "commonjs",
+	},
+	plugins: [
+		new webpack.NormalModuleReplacementPlugin(
+			/\/vscode-languageserver\/lib\/files\.js/,
+			require.resolve('./build/filesFillIn')
+		),
+		new webpack.IgnorePlugin(/vertx/)
+	],
+});
diff --git a/extensions/css-language-features/server/package.json b/extensions/css-language-features/server/package.json
index 6e85706a2f1..512a08bbf85 100644
--- a/extensions/css-language-features/server/package.json
+++ b/extensions/css-language-features/server/package.json
@@ -7,9 +7,10 @@
   "engines": {
     "node": "*"
   },
+  "main": "./out/cssServerMain",
   "dependencies": {
     "vscode-css-languageservice": "^3.0.10-next.3",
-    "vscode-languageserver": "^4.4.0"
+    "vscode-languageserver": "^5.1.0-next.3"
   },
   "devDependencies": {
     "@types/mocha": "2.2.33",
@@ -28,4 +29,4 @@
     "install-server-local": "npm install ../../../../vscode-languageserver-node/server -f",
     "test": "../../../node_modules/.bin/mocha"
   }
-}
+}
\ No newline at end of file
diff --git a/extensions/css-language-features/server/src/pathCompletion.ts b/extensions/css-language-features/server/src/pathCompletion.ts
index 4ea06882be2..960e62df854 100644
--- a/extensions/css-language-features/server/src/pathCompletion.ts
+++ b/extensions/css-language-features/server/src/pathCompletion.ts
@@ -100,16 +100,19 @@ function stripQuotes(fullValue: string) {
  * Get a list of path suggestions. Folder suggestions are suffixed with a slash.
  */
 function providePaths(valueBeforeCursor: string, activeDocFsPath: string, root?: string): string[] {
-	if (startsWith(valueBeforeCursor, '/') && !root) {
-		return [];
-	}
-
 	const lastIndexOfSlash = valueBeforeCursor.lastIndexOf('/');
 	const valueBeforeLastSlash = valueBeforeCursor.slice(0, lastIndexOfSlash + 1);
 
-	const parentDir = startsWith(valueBeforeCursor, '/')
-		? path.resolve(root, '.' + valueBeforeLastSlash)
-		: path.resolve(activeDocFsPath, '..', valueBeforeLastSlash);
+	const startsWithSlash = startsWith(valueBeforeCursor, '/');
+	let parentDir: string;
+	if (startsWithSlash) {
+		if (!root) {
+			return [];
+		}
+		parentDir = path.resolve(root, '.' + valueBeforeLastSlash);
+	} else {
+		parentDir = path.resolve(activeDocFsPath, '..', valueBeforeLastSlash);
+	}
 
 	try {
 		return fs.readdirSync(parentDir).map(f => {
diff --git a/extensions/css-language-features/server/yarn.lock b/extensions/css-language-features/server/yarn.lock
index c2ae2ced51a..58d1e5b3d35 100644
--- a/extensions/css-language-features/server/yarn.lock
+++ b/extensions/css-language-features/server/yarn.lock
@@ -205,35 +205,35 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageserver-protocol@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.10.0.tgz#f8dcdf987687f64a26e7c32d498fc781a0e886dc"
+vscode-languageserver-protocol@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.12.0.tgz#5b23501292abad88f0463b01e83ff98e64a37652"
   dependencies:
     vscode-jsonrpc "^3.6.2"
-    vscode-languageserver-types "^3.10.0"
-
-vscode-languageserver-types@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.0.tgz#944e5308f3b36a3f372c766f1a344e903ec9c389"
+    vscode-languageserver-types "^3.12.0"
 
 vscode-languageserver-types@^3.10.1:
   version "3.10.1"
   resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.1.tgz#d5d5f44f688a3b2aa9857dc53cb9cacca73fe35a"
 
-vscode-languageserver@^4.4.0:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-4.4.0.tgz#b6e8b37a739ccb629d92f3635f0099d191c856fa"
+vscode-languageserver-types@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.12.0.tgz#f96051381b6a050b7175b37d6cb5d2f2eb64b944"
+
+vscode-languageserver@^5.1.0-next.3:
+  version "5.1.0-next.3"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-5.1.0-next.3.tgz#352ce1f0f8bdfc47c1236277ebe865e25b087ccd"
   dependencies:
-    vscode-languageserver-protocol "^3.10.0"
-    vscode-uri "^1.0.3"
+    vscode-languageserver-protocol "^3.12.0"
+    vscode-uri "^1.0.5"
 
 vscode-nls@^3.2.4:
   version "3.2.4"
   resolved "https://registry.yarnpkg.com/vscode-nls/-/vscode-nls-3.2.4.tgz#2166b4183c8aea884d20727f5449e62be69fd398"
 
-vscode-uri@^1.0.3:
-  version "1.0.5"
-  resolved "https://registry.yarnpkg.com/vscode-uri/-/vscode-uri-1.0.5.tgz#3b899a8ef71c37f3054d79bdbdda31c7bf36f20d"
+vscode-uri@^1.0.5:
+  version "1.0.6"
+  resolved "https://registry.yarnpkg.com/vscode-uri/-/vscode-uri-1.0.6.tgz#6b8f141b0bbc44ad7b07e94f82f168ac7608ad4d"
 
 wrappy@1:
   version "1.0.2"
diff --git a/extensions/css-language-features/yarn.lock b/extensions/css-language-features/yarn.lock
index a51de5f43ac..958bba3af28 100644
--- a/extensions/css-language-features/yarn.lock
+++ b/extensions/css-language-features/yarn.lock
@@ -127,6 +127,10 @@ path-is-absolute@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
 
+semver@^5.5.0:
+  version "5.5.1"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-5.5.1.tgz#7dfdd8814bdb7cabc7be0fb1d734cfb66c940477"
+
 supports-color@5.4.0:
   version "5.4.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-5.4.0.tgz#1c6b337402c2137605efe19f10fec390f6faab54"
@@ -137,22 +141,23 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageclient@^4.4.0:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-4.4.0.tgz#b05868f6477b6f0c9910b24daae4f3e8c4b65902"
+vscode-languageclient@^5.1.0-next.4:
+  version "5.1.0-next.4"
+  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-5.1.0-next.4.tgz#2f96b4aa198c45f3e897b7f330c597a401ca95f2"
   dependencies:
-    vscode-languageserver-protocol "^3.10.0"
+    semver "^5.5.0"
+    vscode-languageserver-protocol "^3.12.0"
 
-vscode-languageserver-protocol@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.10.0.tgz#f8dcdf987687f64a26e7c32d498fc781a0e886dc"
+vscode-languageserver-protocol@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.12.0.tgz#5b23501292abad88f0463b01e83ff98e64a37652"
   dependencies:
     vscode-jsonrpc "^3.6.2"
-    vscode-languageserver-types "^3.10.0"
+    vscode-languageserver-types "^3.12.0"
 
-vscode-languageserver-types@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.0.tgz#944e5308f3b36a3f372c766f1a344e903ec9c389"
+vscode-languageserver-types@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.12.0.tgz#f96051381b6a050b7175b37d6cb5d2f2eb64b944"
 
 vscode-nls@^3.2.4:
   version "3.2.4"
diff --git a/extensions/html-language-features/.vscodeignore b/extensions/html-language-features/.vscodeignore
index fe4f2396293..8d0ba59e94c 100644
--- a/extensions/html-language-features/.vscodeignore
+++ b/extensions/html-language-features/.vscodeignore
@@ -1,10 +1,27 @@
 test/**
 .vscode/**
-server/tsconfig.json
-server/src/**
-server/test/**
-server/out/test/**
-client/tsconfig.json
+server/.vscode/**
+node_modules/**
+server/node_modules/**
 client/src/**
-**/node_modules/*/lib/esm/**
-**/node_modules/@types/**
\ No newline at end of file
+server/src/**
+client/out/**
+server/out/**
+client/tsconfig.json
+server/tsconfig.json
+server/test/**
+server/bin/**
+server/build/**
+server/yarn.lock
+server/.npmignore
+yarn.lock
+server/extension.webpack.config.js
+extension.webpack.config.js
+!node_modules/vscode-nls/**
+!node_modules/applicationinsights/**
+!node_modules/diagnostic-channel-publishers/**
+!node_modules/diagnostic-channel/**
+!node_modules/semver/**
+!node_modules/vscode-extension-telemetry/**
+!node_modules/zone.js/**
+!server/node_modules/vscode-nls/**
\ No newline at end of file
diff --git a/extensions/html-language-features/client/src/htmlMain.ts b/extensions/html-language-features/client/src/htmlMain.ts
index 68f8b881d3b..589c3afbf92 100644
--- a/extensions/html-language-features/client/src/htmlMain.ts
+++ b/extensions/html-language-features/client/src/htmlMain.ts
@@ -5,6 +5,7 @@
 'use strict';
 
 import * as path from 'path';
+import * as fs from 'fs';
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
 
@@ -33,8 +34,9 @@ export function activate(context: ExtensionContext) {
 	let packageInfo = getPackageInfo(context);
 	telemetryReporter = packageInfo && new TelemetryReporter(packageInfo.name, packageInfo.version, packageInfo.aiKey);
 
-	// The server is implemented in node
-	let serverModule = context.asAbsolutePath(path.join('server', 'out', 'htmlServerMain.js'));
+	let serverMain = readJSONFile(context.asAbsolutePath('./server/package.json')).main;
+	let serverModule = context.asAbsolutePath(path.join('server', serverMain));
+
 	// The debug options for the server
 	let debugOptions = { execArgv: ['--nolazy', '--inspect=6045'] };
 
@@ -157,7 +159,7 @@ export function activate(context: ExtensionContext) {
 }
 
 function getPackageInfo(context: ExtensionContext): IPackageInfo | null {
-	let extensionPackage = require(context.asAbsolutePath('./package.json'));
+	let extensionPackage = readJSONFile(context.asAbsolutePath('./package.json'));
 	if (extensionPackage) {
 		return {
 			name: extensionPackage.name,
@@ -168,6 +170,16 @@ function getPackageInfo(context: ExtensionContext): IPackageInfo | null {
 	return null;
 }
 
+
+function readJSONFile(location: string) {
+	try {
+		return JSON.parse(fs.readFileSync(location).toString());
+	} catch (e) {
+		console.log(`Problems reading ${location}: ${e}`);
+		return {};
+	}
+}
+
 export function deactivate(): Promise<any> {
 	return telemetryReporter ? telemetryReporter.dispose() : Promise.resolve(null);
 }
\ No newline at end of file
diff --git a/extensions/html-language-features/extension.webpack.config.js b/extensions/html-language-features/extension.webpack.config.js
new file mode 100644
index 00000000000..492a0d1f8fd
--- /dev/null
+++ b/extensions/html-language-features/extension.webpack.config.js
@@ -0,0 +1,40 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../shared.webpack.config');
+const CopyWebpackPlugin = require('copy-webpack-plugin');
+const path = require('path');
+
+module.exports = withDefaults({
+	context: path.join(__dirname, 'client'),
+	entry: {
+		extension: './src/htmlMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'htmlMain.js',
+		path: path.join(__dirname, 'client', 'dist'),
+		libraryTarget: "commonjs",
+	},
+	externals: {
+		'./files': 'commonjs', // ignored because it doesn't exist
+	},
+	plugins: [
+		new CopyWebpackPlugin([
+			{ from: './out/*.sh', to: '[name].sh' },
+			{ from: './out/nls.*.json', to: '[name].json' }
+		])
+	]
+});
diff --git a/extensions/html-language-features/package.json b/extensions/html-language-features/package.json
index e55530df063..58228fa32f8 100644
--- a/extensions/html-language-features/package.json
+++ b/extensions/html-language-features/package.json
@@ -174,10 +174,10 @@
   },
   "dependencies": {
     "vscode-extension-telemetry": "0.0.18",
-    "vscode-languageclient": "^4.4.0",
+    "vscode-languageclient": "^5.1.0-next.4",
     "vscode-nls": "^3.2.4"
   },
   "devDependencies": {
     "@types/node": "^8.10.25"
   }
-}
+}
\ No newline at end of file
diff --git a/extensions/html-language-features/server/build/filesFillIn.js b/extensions/html-language-features/server/build/filesFillIn.js
new file mode 100644
index 00000000000..906617384e0
--- /dev/null
+++ b/extensions/html-language-features/server/build/filesFillIn.js
@@ -0,0 +1,5 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+module.exports = {};
\ No newline at end of file
diff --git a/extensions/html-language-features/server/extension.webpack.config.js b/extensions/html-language-features/server/extension.webpack.config.js
new file mode 100644
index 00000000000..e6c50b131db
--- /dev/null
+++ b/extensions/html-language-features/server/extension.webpack.config.js
@@ -0,0 +1,42 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../../shared.webpack.config');
+const path = require('path');
+var webpack = require('webpack');
+
+module.exports = withDefaults({
+	context: path.join(__dirname),
+	entry: {
+		extension: './src/htmlServerMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'htmlServerMain.js',
+		path: path.join(__dirname, 'dist'),
+		libraryTarget: "commonjs",
+	},
+	externals: {
+		'typescript': 'commonjs typescript',
+		"vscode-nls": 'commonjs vscode-nls',
+	},
+	plugins: [
+		new webpack.NormalModuleReplacementPlugin(
+			/\/vscode-languageserver\/lib\/files\.js/,
+			require.resolve('./build/filesFillIn')
+		),
+		new webpack.IgnorePlugin(/vertx/)
+	],
+});
diff --git a/extensions/html-language-features/server/package.json b/extensions/html-language-features/server/package.json
index 9d4b15d815b..f58370909f2 100644
--- a/extensions/html-language-features/server/package.json
+++ b/extensions/html-language-features/server/package.json
@@ -7,10 +7,11 @@
   "engines": {
     "node": "*"
   },
+  "main": "./out/htmlServerMain",
   "dependencies": {
     "vscode-css-languageservice": "^3.0.9",
     "vscode-html-languageservice": "^2.1.3",
-    "vscode-languageserver": "^4.4.0",
+    "vscode-languageserver": "^5.1.0-next.3",
     "vscode-languageserver-types": "^3.10.0",
     "vscode-nls": "^3.2.4",
     "vscode-uri": "^1.0.5"
@@ -32,4 +33,4 @@
     "install-server-local": "npm install ../../../../vscode-languageserver-node/server -f",
     "test": "npm run compile && ../../../node_modules/.bin/mocha"
   }
-}
+}
\ No newline at end of file
diff --git a/extensions/html-language-features/server/src/modes/pathCompletion.ts b/extensions/html-language-features/server/src/modes/pathCompletion.ts
index 9bb123dcaac..05448ed9dd2 100644
--- a/extensions/html-language-features/server/src/modes/pathCompletion.ts
+++ b/extensions/html-language-features/server/src/modes/pathCompletion.ts
@@ -63,16 +63,19 @@ function shouldDoPathCompletion(tag: string, attr: string, value: string) {
  * Get a list of path suggestions. Folder suggestions are suffixed with a slash.
  */
 function providePaths(valueBeforeCursor: string, activeDocFsPath: string, root?: string): string[] {
-	if (startsWith(valueBeforeCursor, '/') && !root) {
-		return [];
-	}
-
 	const lastIndexOfSlash = valueBeforeCursor.lastIndexOf('/');
 	const valueBeforeLastSlash = valueBeforeCursor.slice(0, lastIndexOfSlash + 1);
 
-	const parentDir = startsWith(valueBeforeCursor, '/')
-		? path.resolve(root, '.' + valueBeforeLastSlash)
-		: path.resolve(activeDocFsPath, '..', valueBeforeLastSlash);
+	const startsWithSlash = startsWith(valueBeforeCursor, '/');
+	let parentDir: string;
+	if (startsWithSlash) {
+		if (!root) {
+			return [];
+		}
+		parentDir = path.resolve(root, '.' + valueBeforeLastSlash);
+	} else {
+		parentDir = path.resolve(activeDocFsPath, '..', valueBeforeLastSlash);
+	}
 
 	try {
 		return fs.readdirSync(parentDir).map(f => {
diff --git a/extensions/html-language-features/server/yarn.lock b/extensions/html-language-features/server/yarn.lock
index d642e6bb321..8090a9ec2ce 100644
--- a/extensions/html-language-features/server/yarn.lock
+++ b/extensions/html-language-features/server/yarn.lock
@@ -213,32 +213,32 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageserver-protocol@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.10.0.tgz#f8dcdf987687f64a26e7c32d498fc781a0e886dc"
+vscode-languageserver-protocol@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.12.0.tgz#5b23501292abad88f0463b01e83ff98e64a37652"
   dependencies:
     vscode-jsonrpc "^3.6.2"
-    vscode-languageserver-types "^3.10.0"
+    vscode-languageserver-types "^3.12.0"
 
 vscode-languageserver-types@^3.10.0:
   version "3.10.0"
   resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.0.tgz#944e5308f3b36a3f372c766f1a344e903ec9c389"
 
-vscode-languageserver@^4.4.0:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-4.4.0.tgz#b6e8b37a739ccb629d92f3635f0099d191c856fa"
+vscode-languageserver-types@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.12.0.tgz#f96051381b6a050b7175b37d6cb5d2f2eb64b944"
+
+vscode-languageserver@^5.1.0-next.3:
+  version "5.1.0-next.3"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-5.1.0-next.3.tgz#352ce1f0f8bdfc47c1236277ebe865e25b087ccd"
   dependencies:
-    vscode-languageserver-protocol "^3.10.0"
-    vscode-uri "^1.0.3"
+    vscode-languageserver-protocol "^3.12.0"
+    vscode-uri "^1.0.5"
 
 vscode-nls@^3.2.4:
   version "3.2.4"
   resolved "https://registry.yarnpkg.com/vscode-nls/-/vscode-nls-3.2.4.tgz#2166b4183c8aea884d20727f5449e62be69fd398"
 
-vscode-uri@^1.0.3:
-  version "1.0.3"
-  resolved "https://registry.yarnpkg.com/vscode-uri/-/vscode-uri-1.0.3.tgz#631bdbf716dccab0e65291a8dc25c23232085a52"
-
 vscode-uri@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/vscode-uri/-/vscode-uri-1.0.5.tgz#3b899a8ef71c37f3054d79bdbdda31c7bf36f20d"
diff --git a/extensions/html-language-features/yarn.lock b/extensions/html-language-features/yarn.lock
index f6e965d98ea..3f7b93cdfbe 100644
--- a/extensions/html-language-features/yarn.lock
+++ b/extensions/html-language-features/yarn.lock
@@ -24,9 +24,9 @@ diagnostic-channel@0.2.0:
   dependencies:
     semver "^5.3.0"
 
-semver@^5.3.0:
-  version "5.5.0"
-  resolved "https://registry.yarnpkg.com/semver/-/semver-5.5.0.tgz#dc4bbc7a6ca9d916dee5d43516f0092b58f7b8ab"
+semver@^5.3.0, semver@^5.5.0:
+  version "5.5.1"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-5.5.1.tgz#7dfdd8814bdb7cabc7be0fb1d734cfb66c940477"
 
 vscode-extension-telemetry@0.0.18:
   version "0.0.18"
@@ -38,22 +38,23 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageclient@^4.4.0:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-4.4.0.tgz#b05868f6477b6f0c9910b24daae4f3e8c4b65902"
+vscode-languageclient@^5.1.0-next.4:
+  version "5.1.0-next.4"
+  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-5.1.0-next.4.tgz#2f96b4aa198c45f3e897b7f330c597a401ca95f2"
   dependencies:
-    vscode-languageserver-protocol "^3.10.0"
+    semver "^5.5.0"
+    vscode-languageserver-protocol "^3.12.0"
 
-vscode-languageserver-protocol@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.10.0.tgz#f8dcdf987687f64a26e7c32d498fc781a0e886dc"
+vscode-languageserver-protocol@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.12.0.tgz#5b23501292abad88f0463b01e83ff98e64a37652"
   dependencies:
     vscode-jsonrpc "^3.6.2"
-    vscode-languageserver-types "^3.10.0"
+    vscode-languageserver-types "^3.12.0"
 
-vscode-languageserver-types@^3.10.0:
-  version "3.10.0"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.0.tgz#944e5308f3b36a3f372c766f1a344e903ec9c389"
+vscode-languageserver-types@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.12.0.tgz#f96051381b6a050b7175b37d6cb5d2f2eb64b944"
 
 vscode-nls@^3.2.4:
   version "3.2.4"
diff --git a/extensions/json-language-features/.vscodeignore b/extensions/json-language-features/.vscodeignore
index eea89a1f649..d6de18538dd 100644
--- a/extensions/json-language-features/.vscodeignore
+++ b/extensions/json-language-features/.vscodeignore
@@ -1,11 +1,26 @@
-test/**
 .vscode/**
-client/tsconfig.json
+server/.vscode/**
+node_modules/**
+server/node_modules/**
 client/src/**
-server/bin
-server/tsconfig.json
 server/src/**
+client/out/**
+server/out/**
+client/tsconfig.json
+server/tsconfig.json
 server/test/**
-server/node_modules/@types/**
-**/node_modules/*/lib/esm/**
-**/node_modules/@types/**
\ No newline at end of file
+server/bin/**
+server/build/**
+server/yarn.lock
+server/.npmignore
+yarn.lock
+server/extension.webpack.config.js
+extension.webpack.config.js
+!node_modules/vscode-nls/**
+!node_modules/applicationinsights/**
+!node_modules/diagnostic-channel-publishers/**
+!node_modules/diagnostic-channel/**
+!node_modules/semver/**
+!node_modules/vscode-extension-telemetry/**
+!node_modules/zone.js/**
+!server/node_modules/vscode-nls/**
\ No newline at end of file
diff --git a/extensions/json-language-features/client/src/jsonMain.ts b/extensions/json-language-features/client/src/jsonMain.ts
index 9040304a4f8..88326058e17 100644
--- a/extensions/json-language-features/client/src/jsonMain.ts
+++ b/extensions/json-language-features/client/src/jsonMain.ts
@@ -5,6 +5,7 @@
 'use strict';
 
 import * as path from 'path';
+import * as fs from 'fs';
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
 
@@ -62,8 +63,9 @@ export function activate(context: ExtensionContext) {
 	let packageInfo = getPackageInfo(context);
 	telemetryReporter = packageInfo && new TelemetryReporter(packageInfo.name, packageInfo.version, packageInfo.aiKey);
 
-	// The server is implemented in node
-	let serverModule = context.asAbsolutePath(path.join('server', 'out', 'jsonServerMain.js'));
+	let serverMain = readJSONFile(context.asAbsolutePath('./server/package.json')).main;
+	let serverModule = context.asAbsolutePath(path.join('server', serverMain));
+
 	// The debug options for the server
 	let debugOptions = { execArgv: ['--nolazy', '--inspect=' + (9000 + Math.round(Math.random() * 10000))] };
 
@@ -259,7 +261,7 @@ function getSchemaId(schema: JSONSchemaSettings, rootPath?: string) {
 }
 
 function getPackageInfo(context: ExtensionContext): IPackageInfo | undefined {
-	let extensionPackage = require(context.asAbsolutePath('./package.json'));
+	let extensionPackage = readJSONFile(context.asAbsolutePath('./package.json'));
 	if (extensionPackage) {
 		return {
 			name: extensionPackage.name,
@@ -269,3 +271,13 @@ function getPackageInfo(context: ExtensionContext): IPackageInfo | undefined {
 	}
 	return void 0;
 }
+
+function readJSONFile(location: string) {
+	try {
+		return JSON.parse(fs.readFileSync(location).toString());
+	} catch (e) {
+		console.log(`Problems reading ${location}: ${e}`);
+		return {};
+	}
+
+}
diff --git a/extensions/json-language-features/extension.webpack.config.js b/extensions/json-language-features/extension.webpack.config.js
new file mode 100644
index 00000000000..3e79ca6b74c
--- /dev/null
+++ b/extensions/json-language-features/extension.webpack.config.js
@@ -0,0 +1,40 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../shared.webpack.config');
+const CopyWebpackPlugin = require('copy-webpack-plugin');
+const path = require('path');
+
+module.exports = withDefaults({
+	context: path.join(__dirname, 'client'),
+	entry: {
+		extension: './src/jsonMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'jsonMain.js',
+		path: path.join(__dirname, 'client', 'dist'),
+		libraryTarget: "commonjs",
+	},
+	externals: {
+		'./files': 'commonjs', // ignored because it doesn't exist
+	},
+	plugins: [
+		new CopyWebpackPlugin([
+			{ from: './out/*.sh', to: '[name].sh' },
+			{ from: './out/nls.*.json', to: '[name].json' }
+		])
+	]
+});
diff --git a/extensions/json-language-features/package.json b/extensions/json-language-features/package.json
index a1910651a22..c47a4923ce2 100644
--- a/extensions/json-language-features/package.json
+++ b/extensions/json-language-features/package.json
@@ -101,7 +101,7 @@
   },
   "dependencies": {
     "vscode-extension-telemetry": "0.0.18",
-    "vscode-languageclient": "^4.4.2",
+    "vscode-languageclient": "^5.1.0-next.4",
     "vscode-nls": "^3.2.4"
   },
   "devDependencies": {
diff --git a/extensions/json-language-features/server/build/files.js b/extensions/json-language-features/server/build/files.js
new file mode 100644
index 00000000000..906617384e0
--- /dev/null
+++ b/extensions/json-language-features/server/build/files.js
@@ -0,0 +1,5 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+module.exports = {};
\ No newline at end of file
diff --git a/extensions/json-language-features/server/extension.webpack.config.js b/extensions/json-language-features/server/extension.webpack.config.js
new file mode 100644
index 00000000000..37e4207daac
--- /dev/null
+++ b/extensions/json-language-features/server/extension.webpack.config.js
@@ -0,0 +1,38 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+'use strict';
+
+const withDefaults = require('../../shared.webpack.config');
+const path = require('path');
+var webpack = require('webpack');
+
+module.exports = withDefaults({
+	context: path.join(__dirname),
+	entry: {
+		extension: './src/jsonServerMain.ts',
+	},
+	resolve: {
+		mainFields: ['module', 'main'],
+		extensions: ['.ts', '.js'] // support ts-files and js-files
+	},
+	node: {
+		__dirname: false // leave the __dirname-behaviour intact
+	},
+	output: {
+		filename: 'jsonServerMain.js',
+		path: path.join(__dirname, 'dist'),
+		libraryTarget: "commonjs",
+	},
+	plugins: [
+		new webpack.NormalModuleReplacementPlugin(
+			/\/vscode-languageserver\/lib\/files\.js/,
+			require.resolve('./build/files')
+		),
+		new webpack.IgnorePlugin(/vertx/)
+	],
+});
diff --git a/extensions/json-language-features/server/package.json b/extensions/json-language-features/server/package.json
index 76fc712381c..7ab4df1bbd1 100644
--- a/extensions/json-language-features/server/package.json
+++ b/extensions/json-language-features/server/package.json
@@ -10,11 +10,12 @@
   "bin": {
     "vscode-json-languageserver": "./bin/vscode-json-languageserver"
   },
+  "main": "./dist/jsonServerMain",
   "dependencies": {
     "jsonc-parser": "^2.0.1",
     "request-light": "^0.2.3",
     "vscode-json-languageservice": "^3.1.5",
-    "vscode-languageserver": "^4.4.2",
+    "vscode-languageserver": "^5.1.0-next.3",
     "vscode-nls": "^3.2.4",
     "vscode-uri": "^1.0.5"
   },
@@ -34,4 +35,4 @@
     "install-server-local": "yarn link vscode-languageserver-server",
     "version": "git commit -m \"JSON Language Server $npm_package_version\" package.json"
   }
-}
+}
\ No newline at end of file
diff --git a/extensions/json-language-features/server/yarn.lock b/extensions/json-language-features/server/yarn.lock
index b8eca3bc52b..e1d835c7869 100644
--- a/extensions/json-language-features/server/yarn.lock
+++ b/extensions/json-language-features/server/yarn.lock
@@ -75,22 +75,26 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageserver-protocol@^3.10.3:
-  version "3.10.3"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.10.3.tgz#59841c9602a6a6baab68613c2a47760994657196"
+vscode-languageserver-protocol@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.12.0.tgz#5b23501292abad88f0463b01e83ff98e64a37652"
   dependencies:
     vscode-jsonrpc "^3.6.2"
-    vscode-languageserver-types "^3.10.1"
+    vscode-languageserver-types "^3.12.0"
 
 vscode-languageserver-types@^3.10.1:
   version "3.10.1"
   resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.10.1.tgz#d5d5f44f688a3b2aa9857dc53cb9cacca73fe35a"
 
-vscode-languageserver@^4.4.2:
-  version "4.4.2"
-  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-4.4.2.tgz#600ae9cc7a6ff1e84d93c7807840c2cb5b22821b"
+vscode-languageserver-types@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver-types/-/vscode-languageserver-types-3.12.0.tgz#f96051381b6a050b7175b37d6cb5d2f2eb64b944"
+
+vscode-languageserver@^5.1.0-next.3:
+  version "5.1.0-next.3"
+  resolved "https://registry.yarnpkg.com/vscode-languageserver/-/vscode-languageserver-5.1.0-next.3.tgz#352ce1f0f8bdfc47c1236277ebe865e25b087ccd"
   dependencies:
-    vscode-languageserver-protocol "^3.10.3"
+    vscode-languageserver-protocol "^3.12.0"
     vscode-uri "^1.0.5"
 
 vscode-nls@^3.2.2, vscode-nls@^3.2.4:
diff --git a/extensions/json-language-features/yarn.lock b/extensions/json-language-features/yarn.lock
index cb126a6c120..781800a5a94 100644
--- a/extensions/json-language-features/yarn.lock
+++ b/extensions/json-language-features/yarn.lock
@@ -38,9 +38,9 @@ vscode-jsonrpc@^3.6.2:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/vscode-jsonrpc/-/vscode-jsonrpc-3.6.2.tgz#3b5eef691159a15556ecc500e9a8a0dd143470c8"
 
-vscode-languageclient@^4.4.2:
-  version "4.4.2"
-  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-4.4.2.tgz#a341a7b4ac403e481f011ed4572854646e8968c4"
+vscode-languageclient@^5.1.0-next.4:
+  version "5.1.0-next.4"
+  resolved "https://registry.yarnpkg.com/vscode-languageclient/-/vscode-languageclient-5.1.0-next.4.tgz#2f96b4aa198c45f3e897b7f330c597a401ca95f2"
   dependencies:
     vscode-languageserver-protocol "^3.10.3"