diff --git a/src/vs/workbench/api/electron-browser/mainThreadCommands.ts b/src/vs/workbench/api/electron-browser/mainThreadCommands.ts
index 050e27b59d0..5d693ddb28f 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadCommands.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadCommands.ts
@@ -54,20 +54,18 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 		});
 	}
 
-	$registerCommand(id: string): TPromise<any> {
+	$registerCommand(id: string): void {
 		this._disposables.set(
 			id,
 			CommandsRegistry.registerCommand(id, (accessor, ...args) => this._proxy.$executeContributedCommand(id, ...args))
 		);
-		return undefined;
 	}
 
-	$unregisterCommand(id: string): TPromise<any> {
+	$unregisterCommand(id: string): void {
 		if (this._disposables.has(id)) {
 			this._disposables.get(id).dispose();
 			this._disposables.delete(id);
 		}
-		return undefined;
 	}
 
 	$executeCommand<T>(id: string, args: any[]): Thenable<T> {
diff --git a/src/vs/workbench/api/electron-browser/mainThreadDiagnostics.ts b/src/vs/workbench/api/electron-browser/mainThreadDiagnostics.ts
index e0dcb93f1d7..5051aabba45 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadDiagnostics.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadDiagnostics.ts
@@ -6,7 +6,6 @@
 
 import { IMarkerService, IMarkerData } from 'vs/platform/markers/common/markers';
 import URI, { UriComponents } from 'vs/base/common/uri';
-import { TPromise } from 'vs/base/common/winjs.base';
 import { MainThreadDiagnosticsShape, MainContext, IExtHostContext } from '../node/extHost.protocol';
 import { extHostNamedCustomer } from 'vs/workbench/api/electron-browser/extHostCustomers';
 
@@ -27,18 +26,16 @@ export class MainThreadDiagnostics implements MainThreadDiagnosticsShape {
 		this._activeOwners.forEach(owner => this._markerService.changeAll(owner, undefined));
 	}
 
-	$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): TPromise<any> {
+	$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): void {
 		for (let entry of entries) {
 			let [uri, markers] = entry;
 			this._markerService.changeOne(owner, URI.revive(uri), markers);
 		}
 		this._activeOwners.add(owner);
-		return undefined;
 	}
 
-	$clear(owner: string): TPromise<any> {
+	$clear(owner: string): void {
 		this._markerService.changeAll(owner, undefined);
 		this._activeOwners.delete(owner);
-		return undefined;
 	}
 }
diff --git a/src/vs/workbench/api/electron-browser/mainThreadEditors.ts b/src/vs/workbench/api/electron-browser/mainThreadEditors.ts
index 971d5df9a08..01660eb6a4d 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadEditors.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadEditors.ts
@@ -162,7 +162,7 @@ export class MainThreadEditors implements MainThreadEditorsShape {
 		return undefined;
 	}
 
-	$trySetSelections(id: string, selections: ISelection[]): TPromise<any> {
+	$trySetSelections(id: string, selections: ISelection[]): TPromise<void> {
 		if (!this._documentsAndEditors.getEditor(id)) {
 			return TPromise.wrapError(disposed(`TextEditor(${id})`));
 		}
@@ -170,7 +170,7 @@ export class MainThreadEditors implements MainThreadEditorsShape {
 		return TPromise.as(null);
 	}
 
-	$trySetDecorations(id: string, key: string, ranges: IDecorationOptions[]): TPromise<any> {
+	$trySetDecorations(id: string, key: string, ranges: IDecorationOptions[]): TPromise<void> {
 		if (!this._documentsAndEditors.getEditor(id)) {
 			return TPromise.wrapError(disposed(`TextEditor(${id})`));
 		}
@@ -178,7 +178,7 @@ export class MainThreadEditors implements MainThreadEditorsShape {
 		return TPromise.as(null);
 	}
 
-	$trySetDecorationsFast(id: string, key: string, ranges: number[]): TPromise<any> {
+	$trySetDecorationsFast(id: string, key: string, ranges: number[]): TPromise<void> {
 		if (!this._documentsAndEditors.getEditor(id)) {
 			return TPromise.wrapError(disposed(`TextEditor(${id})`));
 		}
@@ -186,7 +186,7 @@ export class MainThreadEditors implements MainThreadEditorsShape {
 		return TPromise.as(null);
 	}
 
-	$tryRevealRange(id: string, range: IRange, revealType: TextEditorRevealType): TPromise<any> {
+	$tryRevealRange(id: string, range: IRange, revealType: TextEditorRevealType): TPromise<void> {
 		if (!this._documentsAndEditors.getEditor(id)) {
 			return TPromise.wrapError(disposed(`TextEditor(${id})`));
 		}
@@ -194,7 +194,7 @@ export class MainThreadEditors implements MainThreadEditorsShape {
 		return undefined;
 	}
 
-	$trySetOptions(id: string, options: ITextEditorConfigurationUpdate): TPromise<any> {
+	$trySetOptions(id: string, options: ITextEditorConfigurationUpdate): TPromise<void> {
 		if (!this._documentsAndEditors.getEditor(id)) {
 			return TPromise.wrapError(disposed(`TextEditor(${id})`));
 		}
diff --git a/src/vs/workbench/api/electron-browser/mainThreadStorage.ts b/src/vs/workbench/api/electron-browser/mainThreadStorage.ts
index a58f4d0f466..403ddbdde6b 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadStorage.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadStorage.ts
@@ -38,7 +38,7 @@ export class MainThreadStorage implements MainThreadStorageShape {
 		}
 	}
 
-	$setValue(shared: boolean, key: string, value: any): TPromise<any> {
+	$setValue(shared: boolean, key: string, value: any): TPromise<void> {
 		let jsonValue: any;
 		try {
 			jsonValue = JSON.stringify(value);
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 18227ca7781..4db1eb79fae 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -102,8 +102,8 @@ export interface IMainContext extends IRPCProtocol {
 // --- main thread
 
 export interface MainThreadCommandsShape extends IDisposable {
-	$registerCommand(id: string): TPromise<any>;
-	$unregisterCommand(id: string): TPromise<any>;
+	$registerCommand(id: string): void;
+	$unregisterCommand(id: string): void;
 	$executeCommand<T>(id: string, args: any[]): Thenable<T>;
 	$getCommands(): Thenable<string[]>;
 }
@@ -114,8 +114,8 @@ export interface MainThreadConfigurationShape extends IDisposable {
 }
 
 export interface MainThreadDiagnosticsShape extends IDisposable {
-	$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): TPromise<any>;
-	$clear(owner: string): TPromise<any>;
+	$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): void;
+	$clear(owner: string): void;
 }
 
 export interface MainThreadDialogOpenOptions {
@@ -152,7 +152,7 @@ export interface MainThreadDocumentContentProvidersShape extends IDisposable {
 
 export interface MainThreadDocumentsShape extends IDisposable {
 	$tryCreateDocument(options?: { language?: string; content?: string; }): TPromise<UriComponents>;
-	$tryOpenDocument(uri: UriComponents): TPromise<any>;
+	$tryOpenDocument(uri: UriComponents): TPromise<void>;
 	$trySaveDocument(uri: UriComponents): TPromise<boolean>;
 }
 
@@ -216,14 +216,14 @@ export interface MainThreadEditorsShape extends IDisposable {
 	$removeTextEditorDecorationType(key: string): void;
 	$tryShowEditor(id: string, position: EditorPosition): TPromise<void>;
 	$tryHideEditor(id: string): TPromise<void>;
-	$trySetOptions(id: string, options: ITextEditorConfigurationUpdate): TPromise<any>;
-	$trySetDecorations(id: string, key: string, ranges: editorCommon.IDecorationOptions[]): TPromise<any>;
-	$trySetDecorationsFast(id: string, key: string, ranges: number[]): TPromise<any>;
-	$tryRevealRange(id: string, range: IRange, revealType: TextEditorRevealType): TPromise<any>;
-	$trySetSelections(id: string, selections: ISelection[]): TPromise<any>;
+	$trySetOptions(id: string, options: ITextEditorConfigurationUpdate): TPromise<void>;
+	$trySetDecorations(id: string, key: string, ranges: editorCommon.IDecorationOptions[]): TPromise<void>;
+	$trySetDecorationsFast(id: string, key: string, ranges: number[]): TPromise<void>;
+	$tryRevealRange(id: string, range: IRange, revealType: TextEditorRevealType): TPromise<void>;
+	$trySetSelections(id: string, selections: ISelection[]): TPromise<void>;
 	$tryApplyEdits(id: string, modelVersionId: number, edits: editorCommon.ISingleEditOperation[], opts: IApplyEditsOptions): TPromise<boolean>;
 	$tryApplyWorkspaceEdit(workspaceResourceEdits: IWorkspaceResourceEdit[]): TPromise<boolean>;
-	$tryInsertSnippet(id: string, template: string, selections: IRange[], opts: IUndoStopOptions): TPromise<any>;
+	$tryInsertSnippet(id: string, template: string, selections: IRange[], opts: IUndoStopOptions): TPromise<boolean>;
 	$getDiffInformation(id: string): TPromise<editorCommon.ILineChange[]>;
 }
 
@@ -352,7 +352,7 @@ export interface MainThreadStatusBarShape extends IDisposable {
 
 export interface MainThreadStorageShape extends IDisposable {
 	$getValue<T>(shared: boolean, key: string): TPromise<T>;
-	$setValue(shared: boolean, key: string, value: any): TPromise<any>;
+	$setValue(shared: boolean, key: string, value: any): TPromise<void>;
 }
 
 export interface MainThreadTelemetryShape extends IDisposable {
diff --git a/src/vs/workbench/test/electron-browser/api/extHostCommands.test.ts b/src/vs/workbench/test/electron-browser/api/extHostCommands.test.ts
index 98029fe424b..4a63beb1958 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostCommands.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostCommands.test.ts
@@ -8,7 +8,6 @@
 import * as assert from 'assert';
 import { ExtHostCommands } from 'vs/workbench/api/node/extHostCommands';
 import { MainThreadCommandsShape } from 'vs/workbench/api/node/extHost.protocol';
-import { TPromise } from 'vs/base/common/winjs.base';
 import { CommandsRegistry } from 'vs/platform/commands/common/commands';
 import { OneGetThreadService } from './testThreadService';
 import { mock } from 'vs/workbench/test/electron-browser/api/mock';
@@ -21,12 +20,11 @@ suite('ExtHostCommands', function () {
 		let lastUnregister: string;
 
 		const shape = new class extends mock<MainThreadCommandsShape>() {
-			$registerCommand(id: string): TPromise<any> {
-				return undefined;
+			$registerCommand(id: string): void {
+				//
 			}
-			$unregisterCommand(id: string): TPromise<any> {
+			$unregisterCommand(id: string): void {
 				lastUnregister = id;
-				return undefined;
 			}
 		};
 
@@ -42,12 +40,11 @@ suite('ExtHostCommands', function () {
 		let unregisterCounter = 0;
 
 		const shape = new class extends mock<MainThreadCommandsShape>() {
-			$registerCommand(id: string): TPromise<any> {
-				return undefined;
+			$registerCommand(id: string): void {
+				//
 			}
-			$unregisterCommand(id: string): TPromise<any> {
+			$unregisterCommand(id: string): void {
 				unregisterCounter += 1;
-				return undefined;
 			}
 		};
 
diff --git a/src/vs/workbench/test/electron-browser/api/extHostDiagnostics.test.ts b/src/vs/workbench/test/electron-browser/api/extHostDiagnostics.test.ts
index d62022fb25b..95bee35a936 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostDiagnostics.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostDiagnostics.test.ts
@@ -11,18 +11,17 @@ import Severity from 'vs/base/common/severity';
 import { DiagnosticCollection } from 'vs/workbench/api/node/extHostDiagnostics';
 import { Diagnostic, DiagnosticSeverity, Range } from 'vs/workbench/api/node/extHostTypes';
 import { MainThreadDiagnosticsShape } from 'vs/workbench/api/node/extHost.protocol';
-import { TPromise } from 'vs/base/common/winjs.base';
 import { IMarkerData } from 'vs/platform/markers/common/markers';
 import { mock } from 'vs/workbench/test/electron-browser/api/mock';
 
 suite('ExtHostDiagnostics', () => {
 
 	class DiagnosticsShape extends mock<MainThreadDiagnosticsShape>() {
-		$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): TPromise<any> {
-			return TPromise.as(null);
+		$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): void {
+			//
 		}
-		$clear(owner: string): TPromise<any> {
-			return TPromise.as(null);
+		$clear(owner: string): void {
+			//
 		}
 	}
 
@@ -165,7 +164,7 @@ suite('ExtHostDiagnostics', () => {
 
 		let lastEntries: [UriComponents, IMarkerData[]][];
 		let collection = new DiagnosticCollection('test', new class extends DiagnosticsShape {
-			$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): TPromise<any> {
+			$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): void {
 				lastEntries = entries;
 				return super.$changeMany(owner, entries);
 			}
@@ -239,7 +238,7 @@ suite('ExtHostDiagnostics', () => {
 
 		let lastEntries: [UriComponents, IMarkerData[]][];
 		let collection = new DiagnosticCollection('test', new class extends DiagnosticsShape {
-			$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): TPromise<any> {
+			$changeMany(owner: string, entries: [UriComponents, IMarkerData[]][]): void {
 				lastEntries = entries;
 				return super.$changeMany(owner, entries);
 			}