diff --git a/examples/umd/index.html b/examples/umd/index.html
index 9e9786f..de65adf 100644
--- a/examples/umd/index.html
+++ b/examples/umd/index.html
@@ -15,7 +15,7 @@
     <code id="path"></code>
     <div
       id="container"
-      style="width:800px;height:600px;border:1px solid grey"
+      style="width: 800px; height: 600px; border: 1px solid grey;"
     ></div>
 
     <style>
@@ -54,7 +54,7 @@
         'vs/language/yaml/monaco.contribution',
         'prettier/standalone',
         'prettier/parser-yaml',
-      ], function() {
+      ], function () {
         const yaml = `p1: `;
         const modelUri = monaco.Uri.parse('a://b/foo.json');
         const editor = monaco.editor.create(
@@ -102,7 +102,9 @@
           ],
         });
 
-        require(['vs/editor/contrib/quickOpen/quickOpen'], async quickOpen => {
+        require(['vs/editor/contrib/quickOpen/quickOpen'], async (
+          quickOpen
+        ) => {
           const NEVER_CANCEL_TOKEN = {
             isCancellationRequested: false,
             onCancellationRequested: () => Event.NONE,
@@ -122,7 +124,7 @@
               if (symbol && symbol.children && symbol.children.length) {
                 target =
                   _recur(
-                    symbol.children.find(child =>
+                    symbol.children.find((child) =>
                       child.range.containsPosition(position)
                     )
                   ) || symbol;
diff --git a/package.json b/package.json
index b5bf5f3..dd656d7 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "bundle:esm": "node ./scripts/bundle-esm",
     "build": "yarn compile && yarn bundle",
     "prepare": "husky install && yarn build",
-    "lint": "prettier \"**/*.{css,js,json,jsx,html,md,ts}\" --check"
+    "lint": "prettier --check ."
   },
   "main": "./lib/esm/monaco.contribution.js",
   "module": "./lib/esm/monaco.contribution.js",
@@ -34,7 +34,8 @@
     "url": "https://github.com/pengx17/monaco-yaml/issues"
   },
   "dependencies": {
-    "yaml-language-server": "^0.11.1"
+    "js-yaml": "^3.14.1",
+    "yaml-ast-parser-custom-tags": "^0.0.43"
   },
   "devDependencies": {
     "husky": "^5.2.0",
@@ -43,11 +44,12 @@
     "monaco-editor-core": "^0.21.2",
     "monaco-languages": "^2.1.1",
     "monaco-plugin-helpers": "^1.0.3",
-    "prettier": "^1.19.1",
+    "prettier": "2.0.5",
     "requirejs": "^2.3.6",
     "rimraf": "^2.6.2",
     "typescript": "^4.2.3",
-    "uglify-es": "^3.3.9"
+    "uglify-es": "^3.3.9",
+    "yaml-language-server": "^0.11.1"
   },
   "prettier": {
     "singleQuote": true,
@@ -55,7 +57,7 @@
     "semi": true
   },
   "lint-staged": {
-    "src/*.{json,scss,html,ts,js,jsx}|scripts/*.js": [
+    "*.{css,json,md,html,ts,js,jsx,yaml}": [
       "prettier --write"
     ]
   }
diff --git a/scripts/bundle-umd.js b/scripts/bundle-umd.js
index c2696f2..85f3662 100644
--- a/scripts/bundle-umd.js
+++ b/scripts/bundle-umd.js
@@ -54,7 +54,7 @@ function bundleOne(moduleId, exclude) {
         },
       ],
     },
-    function() {
+    function () {
       const devFilePath = path.join(REPO_ROOT, 'lib/dev/' + moduleId + '.js');
       const minFilePath = path.join(REPO_ROOT, 'lib/min/' + moduleId + '.js');
       const fileContents = fs.readFileSync(devFilePath).toString();
diff --git a/src/fillers/monaco-editor-amd.ts b/src/fillers/monaco-editor-amd.ts
new file mode 100644
index 0000000..e870a73
--- /dev/null
+++ b/src/fillers/monaco-editor-amd.ts
@@ -0,0 +1,12 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+// Resolves with the global monaco API
+
+declare var define;
+
+define([], function () {
+  return (<any>self).monaco;
+});
diff --git a/src/languageFeatures.ts b/src/languageFeatures.ts
index aa07073..ee86855 100644
--- a/src/languageFeatures.ts
+++ b/src/languageFeatures.ts
@@ -58,13 +58,13 @@ export class DiagnosticsAdapter {
 
     this._disposables.push(monaco.editor.onDidCreateModel(onModelAdd));
     this._disposables.push(
-      monaco.editor.onWillDisposeModel(model => {
+      monaco.editor.onWillDisposeModel((model) => {
         onModelRemoved(model);
         this._resetSchema(model.uri);
       })
     );
     this._disposables.push(
-      monaco.editor.onDidChangeModelLanguage(event => {
+      monaco.editor.onDidChangeModelLanguage((event) => {
         onModelRemoved(event.model);
         onModelAdd(event.model);
         this._resetSchema(event.model.uri);
@@ -72,8 +72,8 @@ export class DiagnosticsAdapter {
     );
 
     this._disposables.push(
-      defaults.onDidChange(_ => {
-        monaco.editor.getModels().forEach(model => {
+      defaults.onDidChange((_) => {
+        monaco.editor.getModels().forEach((model) => {
           if (model.getModeId() === this._languageId) {
             onModelRemoved(model);
             onModelAdd(model);
@@ -95,28 +95,28 @@ export class DiagnosticsAdapter {
   }
 
   public dispose(): void {
-    this._disposables.forEach(d => d && d.dispose());
+    this._disposables.forEach((d) => d && d.dispose());
     this._disposables = [];
   }
 
   private _resetSchema(resource: Uri): void {
-    this._worker().then(worker => {
+    this._worker().then((worker) => {
       worker.resetSchema(resource.toString());
     });
   }
 
   private _doValidate(resource: Uri, languageId: string): void {
     this._worker(resource)
-      .then(worker => {
-        return worker.doValidation(resource.toString()).then(diagnostics => {
-          const markers = diagnostics.map(d => toDiagnostics(resource, d));
+      .then((worker) => {
+        return worker.doValidation(resource.toString()).then((diagnostics) => {
+          const markers = diagnostics.map((d) => toDiagnostics(resource, d));
           const model = monaco.editor.getModel(resource);
           if (model.getModeId() === languageId) {
             monaco.editor.setModelMarkers(model, languageId, markers);
           }
         });
       })
-      .then(undefined, err => {
+      .then(undefined, (err) => {
         console.error(err);
       });
   }
@@ -308,10 +308,10 @@ export class CompletionAdapter
     const resource = model.uri;
 
     return this._worker(resource)
-      .then(worker => {
+      .then((worker) => {
         return worker.doComplete(resource.toString(), fromPosition(position));
       })
-      .then(info => {
+      .then((info) => {
         if (!info) {
           return;
         }
@@ -325,7 +325,7 @@ export class CompletionAdapter
         );
 
         const items: monaco.languages.CompletionItem[] = info.items.map(
-          entry => {
+          (entry) => {
             const item: monaco.languages.CompletionItem = {
               label: entry.label,
               insertText: entry.insertText || entry.label,
@@ -416,10 +416,10 @@ export class HoverAdapter implements monaco.languages.HoverProvider {
     const resource = model.uri;
 
     return this._worker(resource)
-      .then(worker => {
+      .then((worker) => {
         return worker.doHover(resource.toString(), fromPosition(position));
       })
-      .then(info => {
+      .then((info) => {
         if (!info) {
           return;
         }
@@ -488,12 +488,12 @@ export class DocumentSymbolAdapter
     const resource = model.uri;
 
     return this._worker(resource)
-      .then(worker => worker.findDocumentSymbols(resource.toString()))
-      .then(items => {
+      .then((worker) => worker.findDocumentSymbols(resource.toString()))
+      .then((items) => {
         if (!items) {
           return;
         }
-        return items.map(item => toDocumentSymbol(item));
+        return items.map((item) => toDocumentSymbol(item));
       });
   }
 }
@@ -507,7 +507,7 @@ function toDocumentSymbol(
     name: item.name,
     kind: toSymbolKind(item.kind),
     selectionRange: toRange(item.selectionRange),
-    children: item.children.map(child => toDocumentSymbol(child)),
+    children: item.children.map((child) => toDocumentSymbol(child)),
     tags: [],
   };
 }
@@ -533,10 +533,10 @@ export class DocumentFormattingEditProvider
   ): Thenable<monaco.editor.ISingleEditOperation[]> {
     const resource = model.uri;
 
-    return this._worker(resource).then(worker => {
+    return this._worker(resource).then((worker) => {
       return worker
         .format(resource.toString(), null, fromFormattingOptions(options))
-        .then(edits => {
+        .then((edits) => {
           if (!edits || edits.length === 0) {
             return;
           }
@@ -558,14 +558,14 @@ export class DocumentRangeFormattingEditProvider
   ): Thenable<monaco.editor.ISingleEditOperation[]> {
     const resource = model.uri;
 
-    return this._worker(resource).then(worker => {
+    return this._worker(resource).then((worker) => {
       return worker
         .format(
           resource.toString(),
           fromRange(range),
           fromFormattingOptions(options)
         )
-        .then(edits => {
+        .then((edits) => {
           if (!edits || edits.length === 0) {
             return;
           }
diff --git a/src/workerManager.ts b/src/workerManager.ts
index 00e2e5f..cddd3bf 100644
--- a/src/workerManager.ts
+++ b/src/workerManager.ts
@@ -40,13 +40,13 @@ export class WorkerManager {
   public getLanguageServiceWorker(...resources: Uri[]): Promise<YAMLWorker> {
     let _client: YAMLWorker;
     return this._getClient()
-      .then(client => {
+      .then((client) => {
         _client = client;
       })
-      .then(_ => {
+      .then((_) => {
         return this._worker.withSyncedResources(resources);
       })
-      .then(_ => _client);
+      .then((_) => _client);
   }
 
   private _stopWorker(): void {
diff --git a/src/yamlWorker.ts b/src/yamlWorker.ts
index d207c06..81b8899 100644
--- a/src/yamlWorker.ts
+++ b/src/yamlWorker.ts
@@ -14,8 +14,8 @@ import * as yamlService from 'yaml-language-server';
 
 let defaultSchemaRequestService;
 if (typeof fetch !== 'undefined') {
-  defaultSchemaRequestService = function(url) {
-    return fetch(url).then(response => response.text());
+  defaultSchemaRequestService = function (url) {
+    return fetch(url).then((response) => response.text());
   };
 }
 
diff --git a/yarn.lock b/yarn.lock
index 53a185f..062a293 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -455,6 +455,14 @@ js-yaml@^3.13.1:
     argparse "^1.0.7"
     esprima "^4.0.0"
 
+js-yaml@^3.14.1:
+  version "3.14.1"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.14.1.tgz#dae812fdb3825fa306609a8717383c50c36a0537"
+  integrity sha512-okMH7OXXJ7YrN9Ok3/SXrnu4iX9yOk+25nqX4imS2npuvTYDmo/QEZoqwZkYaIDk3jVvBOTOIEgEhaLOynBS9g==
+  dependencies:
+    argparse "^1.0.7"
+    esprima "^4.0.0"
+
 json-parse-even-better-errors@^2.3.0:
   version "2.3.1"
   resolved "https://registry.yarnpkg.com/json-parse-even-better-errors/-/json-parse-even-better-errors-2.3.1.tgz#7c47805a94319928e05777405dc12e1f7a4ee02d"
@@ -662,11 +670,6 @@ prettier@2.0.5:
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.0.5.tgz#d6d56282455243f2f92cc1716692c08aa31522d4"
   integrity sha512-7PtVymN48hGcO4fGjybyBSIWDsLU4H4XlvOHfq91pz9kkGlonzwTfYkaIEwiRg/dAJF9YlbsduBAgtYLi+8cFg==
 
-prettier@^1.19.1:
-  version "1.19.1"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
-  integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
-
 pump@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/pump/-/pump-3.0.0.tgz#b4a2116815bde2f4e1ea602354e8c75565107a64"
@@ -957,7 +960,7 @@ wrappy@1:
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
   integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=
 
-yaml-ast-parser-custom-tags@0.0.43:
+yaml-ast-parser-custom-tags@0.0.43, yaml-ast-parser-custom-tags@^0.0.43:
   version "0.0.43"
   resolved "https://registry.yarnpkg.com/yaml-ast-parser-custom-tags/-/yaml-ast-parser-custom-tags-0.0.43.tgz#46968145ce4e24cb03c3312057f0f141b93a7d02"
   integrity sha512-R5063FF/JSAN6qXCmylwjt9PcDH6M0ExEme/nJBzLspc6FJDmHHIqM7xh2WfEmsTJqClF79A9VkXjkAqmZw9SQ==