diff --git a/src/vs/workbench/api/electron-browser/mainThreadSCM.ts b/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
index f08747986cd..685f6242f9c 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadSCM.ts
@@ -62,6 +62,10 @@ class MainThreadSCMResource implements ISCMResource {
 
 class MainThreadSCMProvider implements ISCMProvider {
 
+	private static ID_HANDLE = 0;
+	private _id = `scm${MainThreadSCMProvider.ID_HANDLE++}`;
+	get id(): string { return this._id; }
+
 	private _groups: MainThreadSCMResourceGroup[] = [];
 	private _groupsByHandle: { [handle: number]: MainThreadSCMResourceGroup; } = Object.create(null);
 
@@ -77,7 +81,7 @@ class MainThreadSCMProvider implements ISCMProvider {
 
 	get handle(): number { return this._handle; }
 	get label(): string { return this._label; }
-	get id(): string { return this._id; }
+	get contextValue(): string { return this._contextValue; }
 
 	get commitTemplate(): string | undefined { return this.features.commitTemplate; }
 	get acceptInputCommand(): Command | undefined { return this.features.acceptInputCommand; }
@@ -92,7 +96,7 @@ class MainThreadSCMProvider implements ISCMProvider {
 	constructor(
 		private proxy: ExtHostSCMShape,
 		private _handle: number,
-		private _id: string,
+		private _contextValue: string,
 		private _label: string,
 		@ISCMService scmService: ISCMService,
 		@ICommandService private commandService: ICommandService
diff --git a/src/vs/workbench/parts/scm/electron-browser/scmMenus.ts b/src/vs/workbench/parts/scm/electron-browser/scmMenus.ts
index 3e1850b0dc8..c22ee5b75e8 100644
--- a/src/vs/workbench/parts/scm/electron-browser/scmMenus.ts
+++ b/src/vs/workbench/parts/scm/electron-browser/scmMenus.ts
@@ -34,7 +34,7 @@ export class SCMMenus implements IDisposable {
 	) {
 		this.contextKeyService = contextKeyService.createScoped();
 		const scmProviderKey = this.contextKeyService.createKey<string | undefined>('scmProvider', void 0);
-		scmProviderKey.set(provider.id);
+		scmProviderKey.set(provider.contextValue);
 
 		this.titleMenu = this.menuService.createMenu(MenuId.SCMTitle, this.contextKeyService);
 		this.disposables.push(this.titleMenu);
diff --git a/src/vs/workbench/parts/scm/electron-browser/scmViewlet.ts b/src/vs/workbench/parts/scm/electron-browser/scmViewlet.ts
index 1b84110a573..a7c1eb4f16a 100644
--- a/src/vs/workbench/parts/scm/electron-browser/scmViewlet.ts
+++ b/src/vs/workbench/parts/scm/electron-browser/scmViewlet.ts
@@ -11,7 +11,7 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { chain } from 'vs/base/common/event';
 import { memoize } from 'vs/base/common/decorators';
 import { onUnexpectedError } from 'vs/base/common/errors';
-import { IDisposable, dispose, empty as EmptyDisposable, toDisposable } from 'vs/base/common/lifecycle';
+import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { Builder } from 'vs/base/browser/builder';
 import { ComposedViewsViewlet, CollapsibleView, IViewletViewOptions, IView, IViewOptions } from 'vs/workbench/parts/views/browser/views';
 import { append, $, toggleClass } from 'vs/base/browser/dom';
@@ -68,10 +68,10 @@ function identityProvider(r: ISCMResourceGroup | ISCMResource): string {
 	if (isSCMResource(r)) {
 		const group = r.resourceGroup;
 		const provider = group.provider;
-		return `${provider.id}/${group.id}/${r.sourceUri.toString()}`;
+		return `${provider.contextValue}/${group.id}/${r.sourceUri.toString()}`;
 	} else {
 		const provider = r.provider;
-		return `${provider.id}/${r.id}`;
+		return `${provider.contextValue}/${r.id}`;
 	}
 }
 
@@ -226,12 +226,12 @@ function resourceSorter(a: ISCMResource, b: ISCMResource): number {
 class SourceControlViewDescriptor implements IViewDescriptor {
 
 	get provider(): ISCMProvider { return this._provider; }
-	get id(): string { return this._id; }
+	get id(): string { return this._provider.id; }
 	get name(): string { return this._provider.label; }
 	get ctor(): any { return null; }
 	get location(): ViewLocation { return ViewLocation.SCM; }
 
-	constructor(private _id: string, private _provider: ISCMProvider) {
+	constructor(private _provider: ISCMProvider) {
 
 	}
 }
@@ -402,9 +402,7 @@ export class SCMViewlet extends ComposedViewsViewlet {
 	// private inputBoxContainer: HTMLElement;
 	// private inputBox: InputBox;
 
-	private providerIdHandle = 0;
-	private providerIds = new Map<ISCMProvider, string>();
-	private providerChangeDisposable: IDisposable = EmptyDisposable;
+	// private providers = new Map<string, ISCMProvider>();
 	private disposables: IDisposable[] = [];
 
 	constructor(
@@ -429,59 +427,43 @@ export class SCMViewlet extends ComposedViewsViewlet {
 			telemetryService, storageService, instantiationService, themeService, contextService, contextKeyService, contextMenuService, extensionService);
 	}
 
-	private onDidProvidersChange(): void {
-		this.providerChangeDisposable.dispose();
-		// this.activeProvider = activeProvider;
-
-		const providers = this.scmService.providers;
-
-		if (providers.length === 0) {
-			return;
-		}
-
-		const result = providers.map(provider => {
-			let id = this.providerIds.get(provider);
-
-			if (!id) {
-				id = `scm${this.providerIdHandle++}`;
-				this.providerIds.set(provider, id);
-			}
-
-			const view = new SourceControlViewDescriptor(id, provider);
-
-			return { id, provider, view };
-		});
-
-		// console.log(provider.label);
-
-		ViewsRegistry.registerViews(result.map(r => r.view));
-		this.providerChangeDisposable = toDisposable(() => ViewsRegistry.deregisterViews(result.map(r => r.id), ViewLocation.SCM));
-
-		// if (activeProvider) {
-		// 	const disposables = [];
-
-		// 	// if (activeProvider.onDidChangeCommitTemplate) {
-		// 	// 	disposables.push(activeProvider.onDidChangeCommitTemplate(this.updateInputBox, this));
-		// 	// }
-
-		// 	const id = activeProvider.id;
-		// 	ViewsRegistry.registerViews([new SourceControlViewDescriptor(activeProvider)]);
-
-		// 	disposables.push({
-		// 		dispose: () => {
-		// 			ViewsRegistry.deregisterViews([id], ViewLocation.SCM);
-		// 		}
-		// 	});
-
-		// 	this.providerChangeDisposable = combinedDisposable(disposables);
-		// } else {
-		// 	this.providerChangeDisposable = EmptyDisposable;
-		// }
-
-		// this.updateInputBox();
-		// this.updateTitleArea();
+	private onDidAddProvider(provider: ISCMProvider): void {
+		const view = new SourceControlViewDescriptor(provider);
+		ViewsRegistry.registerViews([view]);
 	}
 
+	private onDidRemoveProvider(provider: ISCMProvider): void {
+		ViewsRegistry.deregisterViews([provider.id], ViewLocation.SCM);
+	}
+
+	// private onDidProvidersChange(): void {
+	// this.activeProvider = activeProvider;
+
+	// if (activeProvider) {
+	// 	const disposables = [];
+
+	// 	// if (activeProvider.onDidChangeCommitTemplate) {
+	// 	// 	disposables.push(activeProvider.onDidChangeCommitTemplate(this.updateInputBox, this));
+	// 	// }
+
+	// 	const id = activeProvider.id;
+	// 	ViewsRegistry.registerViews([new SourceControlViewDescriptor(activeProvider)]);
+
+	// 	disposables.push({
+	// 		dispose: () => {
+	// 			ViewsRegistry.deregisterViews([id], ViewLocation.SCM);
+	// 		}
+	// 	});
+
+	// 	this.providerChangeDisposable = combinedDisposable(disposables);
+	// } else {
+	// 	this.providerChangeDisposable = EmptyDisposable;
+	// }
+
+	// this.updateInputBox();
+	// this.updateTitleArea();
+	// }
+
 	async create(parent: Builder): TPromise<void> {
 		await super.create(parent);
 
@@ -507,9 +489,9 @@ export class SCMViewlet extends ComposedViewsViewlet {
 		// 	.filter(e => e.equals(KeyMod.CtrlCmd | KeyCode.Enter) || e.equals(KeyMod.CtrlCmd | KeyCode.KEY_S))
 		// 	.on(this.onDidAcceptInput, this, this.disposables);
 
-
-		this.onDidProvidersChange();
-		this.scmService.onDidChangeProviders(this.onDidProvidersChange, this, this.disposables);
+		this.scmService.onDidAddProvider(this.onDidAddProvider, this, this.disposables);
+		this.scmService.onDidRemoveProvider(this.onDidRemoveProvider, this, this.disposables);
+		this.scmService.providers.forEach(p => this.onDidAddProvider(p));
 		// this.themeService.onThemeChange(this.update, this, this.disposables);
 
 		// return TPromise.as(null);
diff --git a/src/vs/workbench/services/scm/common/scm.ts b/src/vs/workbench/services/scm/common/scm.ts
index 116e7e5764f..66cc07504cc 100644
--- a/src/vs/workbench/services/scm/common/scm.ts
+++ b/src/vs/workbench/services/scm/common/scm.ts
@@ -44,6 +44,7 @@ export interface ISCMResourceGroup {
 export interface ISCMProvider extends IDisposable {
 	readonly label: string;
 	readonly id: string;
+	readonly contextValue: string;
 	readonly resources: ISCMResourceGroup[];
 	readonly onDidChange: Event<void>;
 	readonly count?: number;
@@ -63,10 +64,9 @@ export interface ISCMInput {
 export interface ISCMService {
 
 	readonly _serviceBrand: any;
+	readonly onDidAddProvider: Event<ISCMProvider>;
+	readonly onDidRemoveProvider: Event<ISCMProvider>;
 	readonly onDidChangeProvider: Event<ISCMProvider>;
-
-	// TODO@joao fix name
-	readonly onDidChangeProviders: Event<void>;
 	readonly providers: ISCMProvider[];
 	readonly input: ISCMInput;
 	activeProvider: ISCMProvider | undefined;
diff --git a/src/vs/workbench/services/scm/common/scmService.ts b/src/vs/workbench/services/scm/common/scmService.ts
index 7e02c3a6626..5313e3e0273 100644
--- a/src/vs/workbench/services/scm/common/scmService.ts
+++ b/src/vs/workbench/services/scm/common/scmService.ts
@@ -45,14 +45,18 @@ export class SCMService implements ISCMService {
 
 	set activeProvider(provider: ISCMProvider | undefined) {
 		this.setActiveSCMProvider(provider);
-		this.storageService.store(DefaultSCMProviderIdStorageKey, provider.id, StorageScope.WORKSPACE);
+		this.storageService.store(DefaultSCMProviderIdStorageKey, provider.contextValue, StorageScope.WORKSPACE);
 	}
 
+	private _providerIds = new Set<string>();
 	private _providers: ISCMProvider[] = [];
 	get providers(): ISCMProvider[] { return [...this._providers]; }
 
-	private _onDidChangeProviders = new Emitter<void>();
-	get onDidChangeProviders(): Event<void> { return this._onDidChangeProviders.event; }
+	private _onDidAddProvider = new Emitter<ISCMProvider>();
+	get onDidAddProvider(): Event<ISCMProvider> { return this._onDidAddProvider.event; }
+
+	private _onDidRemoveProvider = new Emitter<ISCMProvider>();
+	get onDidRemoveProvider(): Event<ISCMProvider> { return this._onDidRemoveProvider.event; }
 
 	private _onDidChangeProvider = new Emitter<ISCMProvider>();
 	get onDidChangeProvider(): Event<ISCMProvider> { return this._onDidChangeProvider.event; }
@@ -86,15 +90,20 @@ export class SCMService implements ISCMService {
 	}
 
 	registerSCMProvider(provider: ISCMProvider): IDisposable {
+		if (this._providerIds.has(provider.id)) {
+			throw new Error(`SCM Provider ${provider.id} already exists.`);
+		}
+
+		this._providerIds.add(provider.id);
 		this._providers.push(provider);
 
 		const defaultProviderId = this.storageService.get(DefaultSCMProviderIdStorageKey, StorageScope.WORKSPACE);
 
-		if (this._providers.length === 1 || defaultProviderId === provider.id) {
+		if (this._providers.length === 1 || defaultProviderId === provider.contextValue) {
 			this.setActiveSCMProvider(provider);
 		}
 
-		this._onDidChangeProviders.fire();
+		this._onDidAddProvider.fire(provider);
 
 		return toDisposable(() => {
 			const index = this._providers.indexOf(provider);
@@ -103,13 +112,14 @@ export class SCMService implements ISCMService {
 				return;
 			}
 
+			this._providerIds.delete(provider.id);
 			this._providers.splice(index, 1);
 
 			if (this.activeProvider === provider) {
 				this.activeProvider = this._providers[0];
 			}
 
-			this._onDidChangeProviders.fire();
+			this._onDidRemoveProvider.fire(provider);
 		});
 	}