diff --git a/src/vs/editor/common/modes.ts b/src/vs/editor/common/modes.ts
index 97a3a1ab3455cff2a2c45ce32c31a9106d48c68d..6b7ae998466a8d3ebd261d2d2bc666322b804c98 100644
--- a/src/vs/editor/common/modes.ts
+++ b/src/vs/editor/common/modes.ts
@@ -676,6 +676,9 @@ export interface SymbolInformation {
  * the [go to symbol](https://code.visualstudio.com/docs/editor/editingevolved#_goto-symbol)-feature.
  */
 export interface DocumentSymbolProvider {
+
+	extensionId?: string;
+
 	/**
 	 * Provide symbol information for the given document.
 	 */
diff --git a/src/vs/monaco.d.ts b/src/vs/monaco.d.ts
index 5867d5cabbbcd0626b7ba0faef6e2a5ff25d7210..9aeabdb729a9e3bfc35b55df83dace2ecb10c644 100644
--- a/src/vs/monaco.d.ts
+++ b/src/vs/monaco.d.ts
@@ -4893,6 +4893,7 @@ declare namespace monaco.languages {
 	 * the [go to symbol](https://code.visualstudio.com/docs/editor/editingevolved#_goto-symbol)-feature.
 	 */
 	export interface DocumentSymbolProvider {
+		extensionId?: string;
 		/**
 		 * Provide symbol information for the given document.
 		 */
diff --git a/src/vs/workbench/api/electron-browser/mainThreadLanguageFeatures.ts b/src/vs/workbench/api/electron-browser/mainThreadLanguageFeatures.ts
index c25c6477b5067640b17a38ddb27858853dc24ebc..1e2e17a94339be642b896935511aa1b36c637bd4 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadLanguageFeatures.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadLanguageFeatures.ts
@@ -97,8 +97,9 @@ export class MainThreadLanguageFeatures implements MainThreadLanguageFeaturesSha
 
 	// --- outline
 
-	$registerOutlineSupport(handle: number, selector: ISerializedDocumentFilter[]): void {
+	$registerOutlineSupport(handle: number, selector: ISerializedDocumentFilter[], extensionId: string): void {
 		this._registrations[handle] = modes.DocumentSymbolProviderRegistry.register(typeConverters.LanguageSelector.from(selector), <modes.DocumentSymbolProvider>{
+			extensionId,
 			provideDocumentSymbols: (model: ITextModel, token: CancellationToken): Thenable<modes.SymbolInformation[]> => {
 				return wireCancellationToken(token, this._proxy.$provideDocumentSymbols(handle, model.uri)).then(MainThreadLanguageFeatures._reviveSymbolInformationDto);
 			}
diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index 1334c6cb44d679ee079171a792ed6d36d67e7732..e3a63ed328db5e5f67af1e5d28403addf9c65e5f 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -285,7 +285,7 @@ export function createApiFactory(
 				return extHostLanguageFeatures.registerRenameProvider(checkSelector(selector), provider);
 			},
 			registerDocumentSymbolProvider(selector: vscode.DocumentSelector, provider: vscode.DocumentSymbolProvider): vscode.Disposable {
-				return extHostLanguageFeatures.registerDocumentSymbolProvider(checkSelector(selector), provider);
+				return extHostLanguageFeatures.registerDocumentSymbolProvider(checkSelector(selector), provider, extension.id);
 			},
 			registerWorkspaceSymbolProvider(provider: vscode.WorkspaceSymbolProvider): vscode.Disposable {
 				return extHostLanguageFeatures.registerWorkspaceSymbolProvider(provider);
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 870a18c23580e9d1438648d60e7bd048a43afc6f..ec48069d253aefb063d0b2a1b3a21432cc82e781 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -263,7 +263,7 @@ export interface ISerializedDocumentFilter {
 
 export interface MainThreadLanguageFeaturesShape extends IDisposable {
 	$unregister(handle: number): void;
-	$registerOutlineSupport(handle: number, selector: ISerializedDocumentFilter[]): void;
+	$registerOutlineSupport(handle: number, selector: ISerializedDocumentFilter[], extensionId: string): void;
 	$registerCodeLensSupport(handle: number, selector: ISerializedDocumentFilter[], eventHandle: number): void;
 	$emitCodeLensEvent(eventHandle: number, event?: any): void;
 	$registerDeclaractionSupport(handle: number, selector: ISerializedDocumentFilter[]): void;
diff --git a/src/vs/workbench/api/node/extHostLanguageFeatures.ts b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
index a5c89164b99f5b83daa5d5f317103696ebb4e508..44222b9b03b4cf990f3da9bdc642626694eb5df0 100644
--- a/src/vs/workbench/api/node/extHostLanguageFeatures.ts
+++ b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
@@ -928,9 +928,9 @@ export class ExtHostLanguageFeatures implements ExtHostLanguageFeaturesShape {
 
 	// --- outline
 
-	registerDocumentSymbolProvider(selector: vscode.DocumentSelector, provider: vscode.DocumentSymbolProvider): vscode.Disposable {
+	registerDocumentSymbolProvider(selector: vscode.DocumentSelector, provider: vscode.DocumentSymbolProvider, extensionId?: string): vscode.Disposable {
 		const handle = this._addNewAdapter(new OutlineAdapter(this._documents, provider));
-		this._proxy.$registerOutlineSupport(handle, this._transformDocumentSelector(selector));
+		this._proxy.$registerOutlineSupport(handle, this._transformDocumentSelector(selector), extensionId);
 		return this._createDisposable(handle);
 	}
 
diff --git a/src/vs/workbench/parts/outline/electron-browser/outlineModel.ts b/src/vs/workbench/parts/outline/electron-browser/outlineModel.ts
index d258c920d05af644114c26cedaedd0bb2a0307c0..98724108c694087f49217f3da64c163022642c52 100644
--- a/src/vs/workbench/parts/outline/electron-browser/outlineModel.ts
+++ b/src/vs/workbench/parts/outline/electron-browser/outlineModel.ts
@@ -14,10 +14,9 @@ import { Range } from 'vs/editor/common/core/range';
 import { values } from 'vs/base/common/map';
 
 export function getOutline(model: ITextModel): TPromise<OutlineItemGroup>[] {
-	return DocumentSymbolProviderRegistry.ordered(model).map((provider, i) => {
-		let source = `provider${i}`;
+	return DocumentSymbolProviderRegistry.ordered(model).map(provider => {
 		return asWinJsPromise(token => provider.provideDocumentSymbols(model, token)).then(result => {
-			let group = new OutlineItemGroup(source);
+			let group = new OutlineItemGroup(provider.extensionId);
 			for (const info of result) {
 				let child = asOutlineItem(info, group);
 				group.children.set(child.id, child);
@@ -25,7 +24,7 @@ export function getOutline(model: ITextModel): TPromise<OutlineItemGroup>[] {
 			return group;
 		}, err => {
 			//todo@joh capture error in group
-			return new OutlineItemGroup(source);
+			return new OutlineItemGroup(provider.extensionId);
 		});
 	});
 }