diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index e437b85e713bfe6fe596254d0e8f33cb3937dd6e..1fb83005189d9b0d187dfa145ddda63578afe240 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -532,13 +532,17 @@ declare namespace vscode {
 		 * The size in spaces a tab takes. This is used for two purposes:
 		 *  - the rendering width of a tab character;
 		 *  - the number of spaces to insert when [insertSpaces](#TextEditorOptions.insertSpaces) is true.
+		 * When getting a text editor's options, this property will always be a number (resolved).
+		 * When setting a text editor's options, this property is optional and it can be a number or `"auto"`.
 		 */
-		tabSize: number | string;
+		tabSize?: number | string;
 
 		/**
 		 * When pressing Tab insert [n](#TextEditorOptions.tabSize) spaces.
+		 * When getting a text editor's options, this property will always be a boolean (resolved).
+		 * When setting a text editor's options, this property is optional and it can be a boolean or `"auto"`.
 		 */
-		insertSpaces: boolean | string;
+		insertSpaces?: boolean | string;
 	}
 
 	/**
@@ -3104,7 +3108,7 @@ declare namespace vscode {
 		/**
 		 * The folder that is open in VS Code. `undefined` when no folder
 		 * has been opened.
-		 * 
+		 *
 		 * @readonly
 		 */
 		export let rootPath: string;
diff --git a/src/vs/workbench/api/node/extHostEditors.ts b/src/vs/workbench/api/node/extHostEditors.ts
index a56205bd4f58169337fe7119223b480080345ef3..14c89c8daf49ccc543c3ed61229369d8c80afd80 100644
--- a/src/vs/workbench/api/node/extHostEditors.ts
+++ b/src/vs/workbench/api/node/extHostEditors.ts
@@ -11,12 +11,12 @@ import {TPromise} from 'vs/base/common/winjs.base';
 import {Remotable, IThreadService} from 'vs/platform/thread/common/thread';
 import {ExtHostModelService, ExtHostDocumentData} from 'vs/workbench/api/node/extHostDocuments';
 import {Selection, Range, Position, EditorOptions} from './extHostTypes';
-import {ISingleEditOperation, ISelection, IRange, IInternalIndentationOptions, IEditor, EditorType, ICommonCodeEditor, ICommonDiffEditor, IDecorationRenderOptions, IRangeWithMessage} from 'vs/editor/common/editorCommon';
+import {ISingleEditOperation, ISelection, IRange, IEditor, EditorType, ICommonCodeEditor, ICommonDiffEditor, IDecorationRenderOptions, IRangeWithMessage} from 'vs/editor/common/editorCommon';
 import {ICodeEditorService} from 'vs/editor/common/services/codeEditorService';
 import {IWorkbenchEditorService} from 'vs/workbench/services/editor/common/editorService';
 import {Position as EditorPosition} from 'vs/platform/editor/common/editor';
 import {IModelService} from 'vs/editor/common/services/modelService';
-import {MainThreadEditorsTracker, TextEditorRevealType, MainThreadTextEditor, ITextEditorConfiguration} from 'vs/workbench/api/node/mainThreadEditors';
+import {MainThreadEditorsTracker, TextEditorRevealType, MainThreadTextEditor, ITextEditorConfigurationUpdate, ITextEditorConfiguration} from 'vs/workbench/api/node/mainThreadEditors';
 import * as TypeConverters from './extHostTypeConverters';
 import {TextDocument, TextEditorSelectionChangeEvent, TextEditorOptionsChangeEvent, TextEditorOptions, TextEditorViewColumnChangeEvent, ViewColumn} from 'vscode';
 import {EventType} from 'vs/workbench/common/events';
@@ -697,7 +697,7 @@ export class MainThreadEditors {
 		this._textEditorsMap[id].revealRange(range, revealType);
 	}
 
-	_trySetOptions(id: string, options: IInternalIndentationOptions): TPromise<any> {
+	_trySetOptions(id: string, options: ITextEditorConfigurationUpdate): TPromise<any> {
 		if (!this._textEditorsMap[id]) {
 			return TPromise.wrapError('TextEditor disposed');
 		}
diff --git a/src/vs/workbench/api/node/extHostTypes.ts b/src/vs/workbench/api/node/extHostTypes.ts
index ab295e73a0c40daea4edbc8f722e10875d9722c0..0905bb768d44b6fd6b1834dfcb26876b4fb2692c 100644
--- a/src/vs/workbench/api/node/extHostTypes.ts
+++ b/src/vs/workbench/api/node/extHostTypes.ts
@@ -37,8 +37,8 @@ export class Disposable {
 }
 
 export interface EditorOptions {
-	tabSize: number;
-	insertSpaces: boolean;
+	tabSize: number | string;
+	insertSpaces: boolean | string;
 }
 
 export class Position {
diff --git a/src/vs/workbench/api/node/mainThreadEditors.ts b/src/vs/workbench/api/node/mainThreadEditors.ts
index eb0e7ed6e0f3a3c89901a30fc88aa7c149f53b82..78babf273949779836dc488bec94a42483f3a0c2 100644
--- a/src/vs/workbench/api/node/mainThreadEditors.ts
+++ b/src/vs/workbench/api/node/mainThreadEditors.ts
@@ -15,12 +15,12 @@ import {Range} from 'vs/editor/common/core/range';
 import {Selection} from 'vs/editor/common/core/selection';
 
 export interface ITextEditorConfigurationUpdate {
-	tabSize?: number;
-	insertSpaces?: boolean;
+	tabSize?: number | string;
+	insertSpaces?: boolean | string;
 }
 export interface ITextEditorConfiguration {
-	tabSize: number;
-	insertSpaces: boolean;
+	tabSize: number | string;
+	insertSpaces: boolean | string;
 }
 
 function configurationsEqual(a:ITextEditorConfiguration, b:ITextEditorConfiguration) {