diff --git a/src/vs/workbench/api/electron-browser/mainThreadSCM.ts b/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
index f2f391a084a..e26b516c369 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
@@ -15,6 +15,7 @@ import { ExtHostContext, MainThreadSCMShape, ExtHostSCMShape, SCMProviderFeature
 import { Command } from 'vs/editor/common/modes';
 import { extHostNamedCustomer } from 'vs/workbench/api/electron-browser/extHostCustomers';
 import { ISplice, Sequence } from 'vs/base/common/sequence';
+import { CancellationToken } from 'vs/base/common/cancellation';
 
 class MainThreadSCMResourceGroup implements ISCMResourceGroup {
 
@@ -73,7 +74,7 @@ class MainThreadSCMResource implements ISCMResource {
 		public decorations: ISCMResourceDecorations
 	) { }
 
-	open(): TPromise<void> {
+	open(): Thenable<void> {
 		return this.proxy.$executeResourceCommand(this.sourceControlHandle, this.groupHandle, this.handle);
 	}
 
@@ -241,7 +242,7 @@ class MainThreadSCMProvider implements ISCMProvider {
 			return TPromise.as(null);
 		}
 
-		return this.proxy.$provideOriginalResource(this.handle, uri)
+		return TPromise.wrap(this.proxy.$provideOriginalResource(this.handle, uri, CancellationToken.None))
 			.then(result => result && URI.revive(result));
 	}
 
@@ -405,7 +406,7 @@ export class MainThreadSCM implements MainThreadSCMShape {
 
 		if (enabled) {
 			repository.input.validateInput = (value, pos): TPromise<IInputValidation | undefined> => {
-				return this._proxy.$validateInput(sourceControlHandle, value, pos).then(result => {
+				return TPromise.wrap(this._proxy.$validateInput(sourceControlHandle, value, pos).then(result => {
 					if (!result) {
 						return undefined;
 					}
@@ -414,7 +415,7 @@ export class MainThreadSCM implements MainThreadSCMShape {
 						message: result[0],
 						type: result[1]
 					};
-				});
+				}));
 			};
 		} else {
 			repository.input.validateInput = () => TPromise.as(undefined);
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 53a68deeee4..85761d96ef7 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -886,10 +886,10 @@ export interface ExtHostTerminalServiceShape {
 }
 
 export interface ExtHostSCMShape {
-	$provideOriginalResource(sourceControlHandle: number, uri: UriComponents): TPromise<UriComponents>;
+	$provideOriginalResource(sourceControlHandle: number, uri: UriComponents, token: CancellationToken): Thenable<UriComponents>;
 	$onInputBoxValueChange(sourceControlHandle: number, value: string): void;
-	$executeResourceCommand(sourceControlHandle: number, groupHandle: number, handle: number): TPromise<void>;
-	$validateInput(sourceControlHandle: number, value: string, cursorPosition: number): TPromise<[string, number] | undefined>;
+	$executeResourceCommand(sourceControlHandle: number, groupHandle: number, handle: number): Thenable<void>;
+	$validateInput(sourceControlHandle: number, value: string, cursorPosition: number): Thenable<[string, number] | undefined>;
 	$setSelectedSourceControls(selectedSourceControlHandles: number[]): Thenable<void>;
 }
 
diff --git a/src/vs/workbench/api/node/extHostSCM.ts b/src/vs/workbench/api/node/extHostSCM.ts
index 6aa5a833d7f..f1996d5ea4b 100644
--- a/src/vs/workbench/api/node/extHostSCM.ts
+++ b/src/vs/workbench/api/node/extHostSCM.ts
@@ -9,7 +9,7 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { Event, Emitter, once } from 'vs/base/common/event';
 import { debounce } from 'vs/base/common/decorators';
 import { dispose, IDisposable } from 'vs/base/common/lifecycle';
-import { asWinJsPromise } from 'vs/base/common/async';
+import { asThenable } from 'vs/base/common/async';
 import { IExtensionDescription } from 'vs/workbench/services/extensions/common/extensions';
 import { ExtHostCommands } from 'vs/workbench/api/node/extHostCommands';
 import { MainContext, MainThreadSCMShape, SCMRawResource, SCMRawResourceSplice, SCMRawResourceSplices, IMainContext, ExtHostSCMShape } from './extHost.protocol';
@@ -18,6 +18,7 @@ import { comparePaths } from 'vs/base/common/comparers';
 import * as vscode from 'vscode';
 import { ISplice } from 'vs/base/common/sequence';
 import { ILogService } from 'vs/platform/log/common/log';
+import { CancellationToken } from 'vs/base/common/cancellation';
 
 type ProviderHandle = number;
 type GroupHandle = number;
@@ -237,14 +238,14 @@ class ExtHostSourceControlResourceGroup implements vscode.SourceControlResourceG
 		return this._resourceStatesMap.get(handle);
 	}
 
-	$executeResourceCommand(handle: number): TPromise<void> {
+	$executeResourceCommand(handle: number): Thenable<void> {
 		const command = this._resourceStatesCommandsMap.get(handle);
 
 		if (!command) {
-			return TPromise.as(null);
+			return Promise.resolve(null);
 		}
 
-		return asWinJsPromise(_ => this._commands.executeCommand(command.command, ...command.arguments));
+		return asThenable(() => this._commands.executeCommand(command.command, ...command.arguments));
 	}
 
 	_takeResourceStateSnapshot(): SCMRawResourceSplice[] {
@@ -558,7 +559,7 @@ export class ExtHostSCM implements ExtHostSCMShape {
 		return inputBox;
 	}
 
-	$provideOriginalResource(sourceControlHandle: number, uriComponents: UriComponents): TPromise<UriComponents> {
+	$provideOriginalResource(sourceControlHandle: number, uriComponents: UriComponents, token: CancellationToken): Thenable<UriComponents> {
 		const uri = URI.revive(uriComponents);
 		this.logService.trace('ExtHostSCM#$provideOriginalResource', sourceControlHandle, uri.toString());
 
@@ -568,7 +569,7 @@ export class ExtHostSCM implements ExtHostSCMShape {
 			return TPromise.as(null);
 		}
 
-		return asWinJsPromise(token => sourceControl.quickDiffProvider.provideOriginalResource(uri, token));
+		return asThenable(() => sourceControl.quickDiffProvider.provideOriginalResource(uri, token));
 	}
 
 	$onInputBoxValueChange(sourceControlHandle: number, value: string): TPromise<void> {
@@ -584,7 +585,7 @@ export class ExtHostSCM implements ExtHostSCMShape {
 		return TPromise.as(null);
 	}
 
-	$executeResourceCommand(sourceControlHandle: number, groupHandle: number, handle: number): TPromise<void> {
+	$executeResourceCommand(sourceControlHandle: number, groupHandle: number, handle: number): Thenable<void> {
 		this.logService.trace('ExtHostSCM#$executeResourceCommand', sourceControlHandle, groupHandle, handle);
 
 		const sourceControl = this._sourceControls.get(sourceControlHandle);
@@ -602,7 +603,7 @@ export class ExtHostSCM implements ExtHostSCMShape {
 		return group.$executeResourceCommand(handle);
 	}
 
-	$validateInput(sourceControlHandle: number, value: string, cursorPosition: number): TPromise<[string, number] | undefined> {
+	$validateInput(sourceControlHandle: number, value: string, cursorPosition: number): Thenable<[string, number] | undefined> {
 		this.logService.trace('ExtHostSCM#$validateInput', sourceControlHandle);
 
 		const sourceControl = this._sourceControls.get(sourceControlHandle);
@@ -615,7 +616,7 @@ export class ExtHostSCM implements ExtHostSCMShape {
 			return TPromise.as(undefined);
 		}
 
-		return asWinJsPromise(_ => Promise.resolve(sourceControl.inputBox.validateInput(value, cursorPosition))).then(result => {
+		return asThenable(() => sourceControl.inputBox.validateInput(value, cursorPosition)).then(result => {
 			if (!result) {
 				return TPromise.as(undefined);
 			}
diff --git a/src/vs/workbench/services/scm/common/scm.ts b/src/vs/workbench/services/scm/common/scm.ts
index 7c9243f3735..e6daf562b5c 100644
--- a/src/vs/workbench/services/scm/common/scm.ts
+++ b/src/vs/workbench/services/scm/common/scm.ts
@@ -36,7 +36,7 @@ export interface ISCMResource {
 	readonly resourceGroup: ISCMResourceGroup;
 	readonly sourceUri: URI;
 	readonly decorations: ISCMResourceDecorations;
-	open(): TPromise<void>;
+	open(): Thenable<void>;
 }
 
 export interface ISCMResourceGroup extends ISequence<ISCMResource> {