diff --git a/src/vs/platform/configuration/common/configuration.ts b/src/vs/platform/configuration/common/configuration.ts
index 5685e78cd4172962a0d0343db840123c69483f8f..85e3e00ff4c29d21186fdb415405334422ad3772 100644
--- a/src/vs/platform/configuration/common/configuration.ts
+++ b/src/vs/platform/configuration/common/configuration.ts
@@ -43,7 +43,7 @@ export interface IConfigurationService {
 	 * Returns the defined keys of configurations in the different scopes
 	 * the key is defined.
 	 */
-	keys(): IConfigurationKeys;
+	keys(overrides?: IConfigurationOverrides): IConfigurationKeys;
 
 	/**
 	 * Similar to #getConfiguration() but ensures that the latest configuration
@@ -91,6 +91,7 @@ export interface IConfigurationKeys {
 	default: string[];
 	user: string[];
 	workspace: string[];
+	folder: string[];
 }
 
 /**
@@ -268,11 +269,13 @@ export class Configuration<T> {
 		};
 	}
 
-	keys(): IConfigurationKeys {
+	keys(overrides: IConfigurationOverrides = {}): IConfigurationKeys {
+		const folderConfigurationModel = this.getFolderConfigurationModelForResource(overrides.resource);
 		return {
 			default: this._defaults.keys,
 			user: this._user.keys,
-			workspace: this._workspaceConfiguration.keys
+			workspace: this._workspaceConfiguration.keys,
+			folder: folderConfigurationModel ? folderConfigurationModel.keys : []
 		};
 	}
 
diff --git a/src/vs/platform/configuration/node/configurationService.ts b/src/vs/platform/configuration/node/configurationService.ts
index 5ce78912ee23f9a00db5666c6646cbe9058bbce4..afe3e8d1cf7c69343cedbb2a992a537e9ebd5cf2 100644
--- a/src/vs/platform/configuration/node/configurationService.ts
+++ b/src/vs/platform/configuration/node/configurationService.ts
@@ -72,12 +72,12 @@ export class ConfigurationService<T> extends Disposable implements IConfiguratio
 		return this.configuration().getValue<C>(section, options);
 	}
 
-	public lookup<C>(key: string, options?: IConfigurationOverrides): IConfigurationValue<C> {
-		return this.configuration().lookup<C>(key, options);
+	public lookup<C>(key: string, overrides?: IConfigurationOverrides): IConfigurationValue<C> {
+		return this.configuration().lookup<C>(key, overrides);
 	}
 
-	public keys(): IConfigurationKeys {
-		return this.configuration().keys();
+	public keys(overrides?: IConfigurationOverrides): IConfigurationKeys {
+		return this.configuration().keys(overrides);
 	}
 
 	public values<V>(): IConfigurationValues {
diff --git a/src/vs/platform/configuration/test/common/testConfigurationService.ts b/src/vs/platform/configuration/test/common/testConfigurationService.ts
index 2f7161f56df0f3bc05368e86310f0d0ecf32c7de..a49f1aff2ddbf6149ce39799dc4aac21c5139d0d 100644
--- a/src/vs/platform/configuration/test/common/testConfigurationService.ts
+++ b/src/vs/platform/configuration/test/common/testConfigurationService.ts
@@ -50,7 +50,8 @@ export class TestConfigurationService extends EventEmitter implements IConfigura
 		return {
 			default: getConfigurationKeys(),
 			user: Object.keys(this.configuration),
-			workspace: []
+			workspace: [],
+			folder: []
 		};
 	}
 
diff --git a/src/vs/platform/telemetry/test/electron-browser/telemetryService.test.ts b/src/vs/platform/telemetry/test/electron-browser/telemetryService.test.ts
index 6acd2f7754a2b925fcae1688d0fe1f592f2eb825..494159a5f564e0c88f21d718e4dd179d483eff2e 100644
--- a/src/vs/platform/telemetry/test/electron-browser/telemetryService.test.ts
+++ b/src/vs/platform/telemetry/test/electron-browser/telemetryService.test.ts
@@ -696,7 +696,7 @@ suite('TelemetryService', () => {
 						folder: null
 					};
 				},
-				keys() { return { default: [], user: [], workspace: [] }; },
+				keys() { return { default: [], user: [], workspace: [], folder: [] }; },
 				values() { return {}; },
 				onDidUpdateConfiguration: emitter.event
 			});
diff --git a/src/vs/workbench/parts/terminal/test/electron-browser/terminalConfigHelper.test.ts b/src/vs/workbench/parts/terminal/test/electron-browser/terminalConfigHelper.test.ts
index c4b3e37919a0a73f814f454f2061bad40418e527..b370e03061b143b55724a5be9ed9ee197c7c40d8 100644
--- a/src/vs/workbench/parts/terminal/test/electron-browser/terminalConfigHelper.test.ts
+++ b/src/vs/workbench/parts/terminal/test/electron-browser/terminalConfigHelper.test.ts
@@ -19,7 +19,7 @@ class MockConfigurationService implements IConfigurationService {
 	public constructor(private configuration: any = {}) { }
 	public reloadConfiguration<T>(section?: string): TPromise<T> { return TPromise.as(this.getConfiguration()); }
 	public lookup<T>(key: string, overrides?: IConfigurationOverrides): IConfigurationValue<T> { return { value: getConfigurationValue<T>(this.getConfiguration(), key), default: getConfigurationValue<T>(this.getConfiguration(), key), user: getConfigurationValue<T>(this.getConfiguration(), key), workspace: void 0, folder: void 0 }; }
-	public keys() { return { default: [], user: [], workspace: [] }; }
+	public keys() { return { default: [], user: [], workspace: [], folder: [] }; }
 	public values() { return {}; }
 	public getConfiguration(): any { return this.configuration; }
 	public getConfigurationData(): any { return null; }
diff --git a/src/vs/workbench/services/configuration/node/configuration.ts b/src/vs/workbench/services/configuration/node/configuration.ts
index 4c506d62a25c775a5efc359cbe79d1778fcf8bc7..2adfbfb452b94dd7f22eb7508970ee22fe41b1b9 100644
--- a/src/vs/workbench/services/configuration/node/configuration.ts
+++ b/src/vs/workbench/services/configuration/node/configuration.ts
@@ -256,8 +256,8 @@ export class WorkspaceService extends Disposable implements IWorkspaceConfigurat
 		return this._configuration.lookup<C>(key, overrides);
 	}
 
-	public keys(): IConfigurationKeys {
-		return this._configuration.keys();
+	public keys(overrides?: IConfigurationOverrides): IConfigurationKeys {
+		return this._configuration.keys(overrides);
 	}
 
 	public values<V>(): IConfigurationValues {
diff --git a/src/vs/workbench/services/configurationResolver/test/node/configurationResolverService.test.ts b/src/vs/workbench/services/configurationResolver/test/node/configurationResolverService.test.ts
index 4ade2612bd48190c187465cb2e5ee442b20091d1..f0b6787391735c78df3e320ade5a24db165391d4 100644
--- a/src/vs/workbench/services/configurationResolver/test/node/configurationResolverService.test.ts
+++ b/src/vs/workbench/services/configurationResolver/test/node/configurationResolverService.test.ts
@@ -343,7 +343,7 @@ class MockConfigurationService implements IConfigurationService {
 	public constructor(private configuration: any = {}) { }
 	public reloadConfiguration<T>(section?: string): TPromise<T> { return TPromise.as(this.getConfiguration()); }
 	public lookup<T>(key: string, overrides?: IConfigurationOverrides): IConfigurationValue<T> { return { value: getConfigurationValue<T>(this.getConfiguration(), key), default: getConfigurationValue<T>(this.getConfiguration(), key), user: getConfigurationValue<T>(this.getConfiguration(), key), workspace: void 0, folder: void 0 }; }
-	public keys() { return { default: [], user: [], workspace: [] }; }
+	public keys() { return { default: [], user: [], workspace: [], folder: [] }; }
 	public values() { return {}; }
 	public getConfiguration(): any { return this.configuration; }
 	public getConfigurationData(): any { return null; }