diff --git a/build/lib/extensions.ts b/build/lib/extensions.ts
index 0c7c21474b92519c5cbd4ec350e4b00cb5b460bd..07db5eac1c6ba3bf658b369623d165eefd971e2b 100644
--- a/build/lib/extensions.ts
+++ b/build/lib/extensions.ts
@@ -48,7 +48,6 @@ function fromLocalWebpack(extensionPath: string, sourceMappingURLBase: string |
 		}
 	}
 
-
 	vsce.listFiles({ cwd: extensionPath, packageManager: vsce.PackageManager.Yarn, packagedDependencies }).then(fileNames => {
 		const files = fileNames
 			.map(fileName => path.join(extensionPath, fileName))
diff --git a/src/vs/base/browser/ui/tree/objectTreeModel.ts b/src/vs/base/browser/ui/tree/objectTreeModel.ts
index 4b6c2b41509d6d570d6c9a5e1f5c48f33af7869f..742aed056ef6aa4818d2fdef7d25ef00c1dc24e8 100644
--- a/src/vs/base/browser/ui/tree/objectTreeModel.ts
+++ b/src/vs/base/browser/ui/tree/objectTreeModel.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { ISpliceable } from 'vs/base/common/sequence';
 import { Iterator, ISequence } from 'vs/base/common/iterator';
 import { IndexTreeModel } from 'vs/base/browser/ui/tree/indexTreeModel';
diff --git a/src/vs/base/common/json.ts b/src/vs/base/common/json.ts
index bed9da5ed526ad7b7bef9e7f01b35e9d8d1c7a10..9158a73fe1e7d8fbca18b0c12e3f43c5a5da075d 100644
--- a/src/vs/base/common/json.ts
+++ b/src/vs/base/common/json.ts
@@ -2,11 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-'use strict';
 
 export const enum ScanError {
 	None = 0,
diff --git a/src/vs/base/common/jsonEdit.ts b/src/vs/base/common/jsonEdit.ts
index 33ab2fdca80909993b928448d133e50cdfa3fa09..485d9f48b4c6e6d37a1245594c4504a0366a72d5 100644
--- a/src/vs/base/common/jsonEdit.ts
+++ b/src/vs/base/common/jsonEdit.ts
@@ -2,7 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
 
 import { ParseError, Node, JSONPath, Segment, parseTree, findNodeAtLocation } from './json';
 import { Edit, format, isEOL, FormattingOptions } from './jsonFormatter';
diff --git a/src/vs/base/common/jsonFormatter.ts b/src/vs/base/common/jsonFormatter.ts
index a2306b5cb28064c6886efa0c1021d73cdb492ca8..df2a97ee5cd7f07ab342499feecff5ca07356cf5 100644
--- a/src/vs/base/common/jsonFormatter.ts
+++ b/src/vs/base/common/jsonFormatter.ts
@@ -2,7 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
 
 import { createScanner, SyntaxKind, ScanError } from './json';
 
diff --git a/src/vs/base/worker/workerMain.ts b/src/vs/base/worker/workerMain.ts
index 986e3ea4da97192060d8e3fde32ce5e5277e7d89..0ec8b7834dc9d6dda82589eb9f3f74b5bb98f664 100644
--- a/src/vs/base/worker/workerMain.ts
+++ b/src/vs/base/worker/workerMain.ts
@@ -4,7 +4,6 @@
  *--------------------------------------------------------------------------------------------*/
 
 (function () {
-	'use strict';
 
 	let MonacoEnvironment = (<any>self).MonacoEnvironment;
 	let monacoBaseUrl = MonacoEnvironment && MonacoEnvironment.baseUrl ? MonacoEnvironment.baseUrl : '../../../';
diff --git a/src/vs/editor/common/services/getIconClasses.ts b/src/vs/editor/common/services/getIconClasses.ts
index d3be6057d80b9e43d4bf97b995deca5ef9cc0b31..7861390e05b16d9ac8d7a43016bde2455e96ca57 100644
--- a/src/vs/editor/common/services/getIconClasses.ts
+++ b/src/vs/editor/common/services/getIconClasses.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { Schemas } from 'vs/base/common/network';
 import { DataUri, basenameOrAuthority } from 'vs/base/common/resources';
 import { URI as uri } from 'vs/base/common/uri';
diff --git a/src/vs/workbench/api/electron-browser/mainThreadClipboard.ts b/src/vs/workbench/api/electron-browser/mainThreadClipboard.ts
index 14c3f9bb644c50e112821c005c3fb4777291caf5..6497256226e931e3aac90684325a6f5ac7d1e11d 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadClipboard.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadClipboard.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { clipboard } from 'electron';
 import { extHostNamedCustomer } from 'vs/workbench/api/electron-browser/extHostCustomers';
 import { MainContext, MainThreadClipboardShape } from '../node/extHost.protocol';
diff --git a/src/vs/workbench/api/node/extHostClipboard.ts b/src/vs/workbench/api/node/extHostClipboard.ts
index 342845ba00df796b9a836d3bcd8052897a6a3561..90c739c54c7ea28a0cf3ea5e6514edbc63a8ae20 100644
--- a/src/vs/workbench/api/node/extHostClipboard.ts
+++ b/src/vs/workbench/api/node/extHostClipboard.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { IMainContext, MainContext, MainThreadClipboardShape } from 'vs/workbench/api/node/extHost.protocol';
 import * as vscode from 'vscode';
 
diff --git a/src/vs/workbench/parts/snippets/electron-browser/snippetCompletionProvider.ts b/src/vs/workbench/parts/snippets/electron-browser/snippetCompletionProvider.ts
index 7d652efad7eff2241e560e74c9d16cc00a1d6542..82bd65b22fa07ab821b28f5d67f14ad2c2776092 100644
--- a/src/vs/workbench/parts/snippets/electron-browser/snippetCompletionProvider.ts
+++ b/src/vs/workbench/parts/snippets/electron-browser/snippetCompletionProvider.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { MarkdownString } from 'vs/base/common/htmlContent';
 import { compare } from 'vs/base/common/strings';
 import { Position } from 'vs/editor/common/core/position';
diff --git a/test/smoke/src/areas/workbench/viewlet.ts b/test/smoke/src/areas/workbench/viewlet.ts
index 84ccb60101226a0381e98e70675b7eff010ae38e..5d478e5a8cfa85defc6214188a0c62f571610222 100644
--- a/test/smoke/src/areas/workbench/viewlet.ts
+++ b/test/smoke/src/areas/workbench/viewlet.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import { Code } from '../../vscode/code';
 
 export abstract class Viewlet {