diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index b1d5160d44e..ef59a9672d0 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -5399,7 +5399,7 @@ declare module 'vscode' {
 		/**
 		 * An event that is emitted when the [configuration](#WorkspaceConfiguration) changed.
 		 */
-		export const onDidChangeConfiguration: Event<void>;
+		export const onDidChangeConfiguration: Event<ConfigurationChangeEvent>;
 
 		/**
 		 * Register a task provider.
@@ -5411,6 +5411,21 @@ declare module 'vscode' {
 		export function registerTaskProvider(type: string, provider: TaskProvider): Disposable;
 	}
 
+	/**
+	 * An event describing the change in Configuration
+	 */
+	export interface ConfigurationChangeEvent {
+
+		/**
+		 * Returns `true` if the given section for the given resource (if provided) has affected.
+		 *
+		 * @param section Configuration name, supports _dotted_ names.
+		 * @param resource A resource Uri.
+		 * @return `true` if the given section for the given resource (if provided) has affected.
+		 */
+		affectsConfiguration(section: string, resource?: Uri): boolean;
+	}
+
 	/**
 	 * Namespace for participating in language-specific editor [features](https://code.visualstudio.com/docs/editor/editingevolved),
 	 * like IntelliSense, code actions, diagnostics etc.
diff --git a/src/vs/workbench/api/node/extHostConfiguration.ts b/src/vs/workbench/api/node/extHostConfiguration.ts
index f7b42446d55..69a4cc1fdfb 100644
--- a/src/vs/workbench/api/node/extHostConfiguration.ts
+++ b/src/vs/workbench/api/node/extHostConfiguration.ts
@@ -37,7 +37,7 @@ type ConfigurationInspect<T> = {
 
 export class ExtHostConfiguration implements ExtHostConfigurationShape {
 
-	private readonly _onDidChangeConfiguration = new Emitter<void>();
+	private readonly _onDidChangeConfiguration = new Emitter<vscode.ConfigurationChangeEvent>();
 	private readonly _proxy: MainThreadConfigurationShape;
 	private readonly _extHostWorkspace: ExtHostWorkspace;
 	private _configuration: Configuration;
@@ -48,13 +48,13 @@ export class ExtHostConfiguration implements ExtHostConfigurationShape {
 		this._configuration = Configuration.parse(data);
 	}
 
-	get onDidChangeConfiguration(): Event<void> {
+	get onDidChangeConfiguration(): Event<vscode.ConfigurationChangeEvent> {
 		return this._onDidChangeConfiguration && this._onDidChangeConfiguration.event;
 	}
 
 	$acceptConfigurationChanged(data: IConfigurationData, eventData: IWorkspaceConfigurationChangeEventData) {
 		this._configuration = Configuration.parse(data);
-		this._onDidChangeConfiguration.fire(undefined);
+		this._onDidChangeConfiguration.fire(this.toConfigurationChangeEvent(eventData));
 	}
 
 	getConfiguration(section?: string, resource?: URI): vscode.WorkspaceConfiguration {
@@ -120,7 +120,7 @@ export class ExtHostConfiguration implements ExtHostConfigurationShape {
 		return <vscode.WorkspaceConfiguration>Object.freeze(result);
 	}
 
-	protected toConfigurationChangeEvent(data: IWorkspaceConfigurationChangeEventData): WorkspaceConfigurationChangeEvent {
+	private toConfigurationChangeEvent(data: IWorkspaceConfigurationChangeEventData): vscode.ConfigurationChangeEvent {
 		const changedConfiguration = new ConfigurationModel(data.changedConfiguration.contents, data.changedConfiguration.keys, data.changedConfiguration.overrides);
 		const changedConfigurationByResource: StrictResourceMap<ConfigurationModel> = new StrictResourceMap<ConfigurationModel>();
 		for (const key of Object.keys(data.changedConfigurationByResource)) {
@@ -128,7 +128,9 @@ export class ExtHostConfiguration implements ExtHostConfigurationShape {
 			const model = data.changedConfigurationByResource[key];
 			changedConfigurationByResource.set(resource, new ConfigurationModel(model.contents, model.keys, model.overrides));
 		}
-		const event = new ConfigurationChangeEvent(changedConfiguration, changedConfigurationByResource);
-		return new WorkspaceConfigurationChangeEvent(event, this._extHostWorkspace.workspace);
+		const event = new WorkspaceConfigurationChangeEvent(new ConfigurationChangeEvent(changedConfiguration, changedConfigurationByResource), this._extHostWorkspace.workspace);
+		return Object.freeze({
+			affectsConfiguration: (section: string, resource?: URI) => event.affectsConfiguration(section, resource)
+		});
 	}
 }
diff --git a/src/vs/workbench/test/electron-browser/api/extHostConfiguration.test.ts b/src/vs/workbench/test/electron-browser/api/extHostConfiguration.test.ts
index 098ad1ccde8..1d750b6730c 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostConfiguration.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostConfiguration.test.ts
@@ -31,12 +31,16 @@ suite('ExtHostConfiguration', function () {
 		if (!shape) {
 			shape = new class extends mock<MainThreadConfigurationShape>() { };
 		}
-		return new ExtHostConfiguration(shape, new ExtHostWorkspace(new TestThreadService(), null), {
+		return new ExtHostConfiguration(shape, new ExtHostWorkspace(new TestThreadService(), null), createConfigurationData(contents));
+	}
+
+	function createConfigurationData(contents: any) {
+		return {
 			defaults: new ConfigurationModel(contents),
 			user: new ConfigurationModel(contents),
 			workspace: new ConfigurationModel(),
 			folders: Object.create(null)
-		});
+		};
 	}
 
 	test('getConfiguration fails regression test 1.7.1 -> 1.8 #15552', function () {
@@ -404,6 +408,74 @@ suite('ExtHostConfiguration', function () {
 			.then(() => assert.ok(false), err => { /* expecting rejection */ });
 	});
 
+	test('configuration change event', (done) => {
+
+		const workspaceFolder = aWorkspaceFolder(URI.file('folder1'), 0);
+		const testObject = new ExtHostConfiguration(
+			new class extends mock<MainThreadConfigurationShape>() { },
+			new ExtHostWorkspace(new TestThreadService(), {
+				'id': 'foo',
+				'folders': [workspaceFolder],
+				'name': 'foo'
+			}),
+			createConfigurationData({
+				'farboo': {
+					'config': false,
+					'updatedconfig': false
+				}
+			})
+		);
+
+		const newConfigData = createConfigurationData({
+			'farboo': {
+				'config': false,
+				'updatedconfig': true,
+				'newConfig': true,
+			}
+		});
+		const changedConfigurationByResource = Object.create({});
+		changedConfigurationByResource[workspaceFolder.uri.toString()] = new ConfigurationModel({
+			'farboo': {
+				'newConfig': true,
+			}
+		}, ['farboo.newConfig']);
+		const configEventData = {
+			changedConfiguration: new ConfigurationModel({
+				'farboo': {
+					'updatedConfig': true,
+				}
+			}, ['farboo.updatedConfig']),
+			changedConfigurationByResource
+		};
+		testObject.onDidChangeConfiguration(e => {
+
+			assert.deepEqual(testObject.getConfiguration().get('farboo'), {
+				'config': false,
+				'updatedconfig': true,
+				'newConfig': true,
+			});
+
+			assert.ok(e.affectsConfiguration('farboo'));
+			assert.ok(e.affectsConfiguration('farboo', workspaceFolder.uri));
+			assert.ok(e.affectsConfiguration('farboo', URI.file('any')));
+
+			assert.ok(e.affectsConfiguration('farboo.updatedConfig'));
+			assert.ok(e.affectsConfiguration('farboo.updatedConfig', workspaceFolder.uri));
+			assert.ok(e.affectsConfiguration('farboo.updatedConfig', URI.file('any')));
+
+			assert.ok(e.affectsConfiguration('farboo.newConfig'));
+			assert.ok(e.affectsConfiguration('farboo.newConfig', workspaceFolder.uri));
+			assert.ok(!e.affectsConfiguration('farboo.newConfig', URI.file('any')));
+
+			assert.ok(!e.affectsConfiguration('farboo.config'));
+			assert.ok(!e.affectsConfiguration('farboo.config', workspaceFolder.uri));
+			assert.ok(!e.affectsConfiguration('farboo.config', URI.file('any')));
+			done();
+		});
+
+		testObject.$acceptConfigurationChanged(newConfigData, configEventData);
+	});
+
 	function aWorkspaceFolder(uri: URI, index: number, name: string = ''): IWorkspaceFolder {
 		return new WorkspaceFolder({ uri, name, index });
 	}