diff --git a/extensions/javascript/src/features/bowerJSONContribution.ts b/extensions/javascript/src/features/bowerJSONContribution.ts
index 31fee9fe089..72c2d848710 100644
--- a/extensions/javascript/src/features/bowerJSONContribution.ts
+++ b/extensions/javascript/src/features/bowerJSONContribution.ts
@@ -30,7 +30,7 @@ export class BowerJSONContribution implements IJSONContribution {
 		return [{ language: 'json', pattern: '**/bower.json' }, { language: 'json', pattern: '**/.bower.json' }];
 	}
 
-	public collectDefaultSuggestions(resource: string, collector: ISuggestionsCollector): Thenable<any> {
+	public collectDefaultSuggestions(_resource: string, collector: ISuggestionsCollector): Thenable<any> {
 		const defaultValue = {
 			'name': '${1:name}',
 			'description': '${2:description}',
@@ -46,7 +46,7 @@ export class BowerJSONContribution implements IJSONContribution {
 		return Promise.resolve(null);
 	}
 
-	public collectPropertySuggestions(resource: string, location: Location, currentWord: string, addValue: boolean, isLast: boolean, collector: ISuggestionsCollector): Thenable<any> | null {
+	public collectPropertySuggestions(_resource: string, location: Location, currentWord: string, addValue: boolean, isLast: boolean, collector: ISuggestionsCollector): Thenable<any> | null {
 		if ((location.matches(['dependencies']) || location.matches(['devDependencies']))) {
 			if (currentWord.length > 0) {
 				const queryUrl = 'https://bower.herokuapp.com/packages/search/' + encodeURIComponent(currentWord);
@@ -85,6 +85,7 @@ export class BowerJSONContribution implements IJSONContribution {
 						collector.error(localize('json.bower.error.repoaccess', 'Request to the bower repository failed: {0}', success.responseText));
 						return 0;
 					}
+					return undefined;
 				}, (error) => {
 					collector.error(localize('json.bower.error.repoaccess', 'Request to the bower repository failed: {0}', error.responseText));
 					return 0;
@@ -113,7 +114,7 @@ export class BowerJSONContribution implements IJSONContribution {
 		return null;
 	}
 
-	public collectValueSuggestions(resource: string, location: Location, collector: ISuggestionsCollector): Thenable<any> {
+	public collectValueSuggestions(_resource: string, location: Location, collector: ISuggestionsCollector): Thenable<any> {
 		if ((location.matches(['dependencies', '*']) || location.matches(['devDependencies', '*']))) {
 			// not implemented. Could be do done calling the bower command. Waiting for web API: https://github.com/bower/registry/issues/26
 			const proposal = new CompletionItem(localize('json.bower.latest.version', 'latest'));
@@ -161,12 +162,12 @@ export class BowerJSONContribution implements IJSONContribution {
 				// ignore
 			}
 			return void 0;
-		}, (error) => {
+		}, () => {
 			return void 0;
 		});
 	}
 
-	public getInfoContribution(resource: string, location: Location): Thenable<MarkedString[] | null> | null {
+	public getInfoContribution(_resource: string, location: Location): Thenable<MarkedString[] | null> | null {
 		if ((location.matches(['dependencies', '*']) || location.matches(['devDependencies', '*']))) {
 			const pack = location.path[location.path.length - 1];
 			if (typeof pack === 'string') {
diff --git a/extensions/javascript/src/features/jsonContributions.ts b/extensions/javascript/src/features/jsonContributions.ts
index ffb9def3487..81f8a66f2c2 100644
--- a/extensions/javascript/src/features/jsonContributions.ts
+++ b/extensions/javascript/src/features/jsonContributions.ts
@@ -47,7 +47,7 @@ export class JSONHoverProvider implements HoverProvider {
 	constructor(private jsonContribution: IJSONContribution) {
 	}
 
-	public provideHover(document: TextDocument, position: Position, token: CancellationToken): Thenable<Hover> | null {
+	public provideHover(document: TextDocument, position: Position, _token: CancellationToken): Thenable<Hover> | null {
 		const fileName = basename(document.fileName);
 		const offset = document.offsetAt(position);
 		const location = getLocation(document.getText(), offset);
@@ -77,7 +77,7 @@ export class JSONCompletionItemProvider implements CompletionItemProvider {
 	constructor(private jsonContribution: IJSONContribution) {
 	}
 
-	public resolveCompletionItem(item: CompletionItem, token: CancellationToken): Thenable<CompletionItem | null> {
+	public resolveCompletionItem(item: CompletionItem, _token: CancellationToken): Thenable<CompletionItem | null> {
 		if (this.jsonContribution.resolveSuggestion) {
 			const resolver = this.jsonContribution.resolveSuggestion(item);
 			if (resolver) {
@@ -87,7 +87,7 @@ export class JSONCompletionItemProvider implements CompletionItemProvider {
 		return Promise.resolve(item);
 	}
 
-	public provideCompletionItems(document: TextDocument, position: Position, token: CancellationToken): Thenable<CompletionList | null> | null {
+	public provideCompletionItems(document: TextDocument, position: Position, _token: CancellationToken): Thenable<CompletionList | null> | null {
 
 		const fileName = basename(document.fileName);
 
diff --git a/extensions/javascript/src/features/packageJSONContribution.ts b/extensions/javascript/src/features/packageJSONContribution.ts
index cba2dcd6673..6abf5f65394 100644
--- a/extensions/javascript/src/features/packageJSONContribution.ts
+++ b/extensions/javascript/src/features/packageJSONContribution.ts
@@ -31,7 +31,7 @@ export class PackageJSONContribution implements IJSONContribution {
 	public constructor(private xhr: XHRRequest) {
 	}
 
-	public collectDefaultSuggestions(fileName: string, result: ISuggestionsCollector): Thenable<any> {
+	public collectDefaultSuggestions(_fileName: string, result: ISuggestionsCollector): Thenable<any> {
 		const defaultValue = {
 			'name': '${1:name}',
 			'description': '${2:description}',
@@ -48,7 +48,7 @@ export class PackageJSONContribution implements IJSONContribution {
 	}
 
 	public collectPropertySuggestions(
-		resource: string,
+		_resource: string,
 		location: Location,
 		currentWord: string,
 		addValue: boolean,
@@ -98,6 +98,7 @@ export class PackageJSONContribution implements IJSONContribution {
 						collector.error(localize('json.npm.error.repoaccess', 'Request to the NPM repository failed: {0}', success.responseText));
 						return 0;
 					}
+					return undefined;
 				}, (error) => {
 					collector.error(localize('json.npm.error.repoaccess', 'Request to the NPM repository failed: {0}', error.responseText));
 					return 0;
@@ -126,7 +127,7 @@ export class PackageJSONContribution implements IJSONContribution {
 	}
 
 	public collectValueSuggestions(
-		fileName: string,
+		_fileName: string,
 		location: Location,
 		result: ISuggestionsCollector
 	): Thenable<any> | null {
@@ -166,7 +167,7 @@ export class PackageJSONContribution implements IJSONContribution {
 						// ignore
 					}
 					return 0;
-				}, (error) => {
+				}, () => {
 					return 0;
 				});
 			}
@@ -213,12 +214,12 @@ export class PackageJSONContribution implements IJSONContribution {
 				// ignore
 			}
 			return [];
-		}, (error) => {
+		}, () => {
 			return [];
 		});
 	}
 
-	public getInfoContribution(fileName: string, location: Location): Thenable<MarkedString[] | null> | null {
+	public getInfoContribution(_fileName: string, location: Location): Thenable<MarkedString[] | null> | null {
 		if ((location.matches(['dependencies', '*']) || location.matches(['devDependencies', '*']) || location.matches(['optionalDependencies', '*']) || location.matches(['peerDependencies', '*']))) {
 			const pack = location.path[location.path.length - 1];
 			if (typeof pack === 'string') {
diff --git a/extensions/javascript/src/javascriptMain.ts b/extensions/javascript/src/javascriptMain.ts
index 11b6a610195..ed2552b87f0 100644
--- a/extensions/javascript/src/javascriptMain.ts
+++ b/extensions/javascript/src/javascriptMain.ts
@@ -16,7 +16,7 @@ export function activate(context: ExtensionContext): any {
 	nls.config({ locale: env.language });
 
 	configureHttpRequest();
-	workspace.onDidChangeConfiguration(e => configureHttpRequest());
+	workspace.onDidChangeConfiguration(() => configureHttpRequest());
 
 	context.subscriptions.push(addJSONProviders(httpRequest.xhr));
 }
diff --git a/extensions/javascript/tsconfig.json b/extensions/javascript/tsconfig.json
index c0601facf73..32325af1b23 100644
--- a/extensions/javascript/tsconfig.json
+++ b/extensions/javascript/tsconfig.json
@@ -6,6 +6,10 @@
 		"lib": [
 			"es2015"
 		],
+		"noImplicitAny": true,
+		"noImplicitReturns": true,
+		"noUnusedLocals": true,
+		"noUnusedParameters": true,
 		"strict": true
 	},
 	"include": [