diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index 1eb9c19adec..6d98286b6ae 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -588,6 +588,24 @@ declare namespace vscode {
 		Underline = 3
 	}
 
+	/**
+	 * Rendering style of the line numbers.
+	 */
+	export enum TextEditorLineNumbersStyle {
+		/**
+		 * Do not render the line numbers.
+		 */
+		Off = 0,
+		/**
+		 * Render the line numbers.
+		 */
+		On = 1,
+		/**
+		 * Render the line numbers with values relative to the primary cursor location.
+		 */
+		Relative = 2
+	}
+
 	/**
 	 * Represents a [text editor](#TextEditor)'s [options](#TextEditor.options).
 	 */
@@ -622,7 +640,7 @@ declare namespace vscode {
 		 * When getting a text editor's options, this property will always be present.
 		 * When setting a text editor's options, this property is optional.
 		 */
-		lineNumbers?: boolean | 'relative';
+		lineNumbers?: TextEditorLineNumbersStyle;
 	}
 
 	/**
diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index 1f0b80ffa12..d38d53cc47a 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -86,6 +86,7 @@ export class ExtHostAPIImplementation {
 	EndOfLine: typeof vscode.EndOfLine;
 	TextDocumentSaveReason: typeof vscode.TextDocumentSaveReason;
 	TextEditorCursorStyle: typeof vscode.TextEditorCursorStyle;
+	TextEditorLineNumbersStyle: typeof vscode.TextEditorLineNumbersStyle;
 	TextEditorSelectionChangeKind: typeof vscode.TextEditorSelectionChangeKind;
 	commands: typeof vscode.commands;
 	window: typeof vscode.window;
@@ -169,6 +170,7 @@ export class ExtHostAPIImplementation {
 		this.TextEditorRevealType = extHostTypes.TextEditorRevealType;
 		this.EndOfLine = extHostTypes.EndOfLine;
 		this.TextEditorCursorStyle = EditorCommon.TextEditorCursorStyle;
+		this.TextEditorLineNumbersStyle = extHostTypes.TextEditorLineNumbersStyle;
 		this.TextEditorSelectionChangeKind = extHostTypes.TextEditorSelectionChangeKind;
 		this.TextDocumentSaveReason = extHostTypes.TextDocumentSaveReason;
 
diff --git a/src/vs/workbench/api/node/extHostTypes.ts b/src/vs/workbench/api/node/extHostTypes.ts
index 8fa4f72f48b..a1ce182b039 100644
--- a/src/vs/workbench/api/node/extHostTypes.ts
+++ b/src/vs/workbench/api/node/extHostTypes.ts
@@ -825,6 +825,12 @@ export enum EndOfLine {
 	CRLF = 2
 }
 
+export enum TextEditorLineNumbersStyle {
+	Off = 0,
+	On = 1,
+	Relative = 2
+}
+
 export enum TextDocumentSaveReason {
 	Explicit = 1,
 	Auto = 2,
diff --git a/src/vs/workbench/api/node/mainThreadEditorsTracker.ts b/src/vs/workbench/api/node/mainThreadEditorsTracker.ts
index 7e7d8750032..55c66278d50 100644
--- a/src/vs/workbench/api/node/mainThreadEditorsTracker.ts
+++ b/src/vs/workbench/api/node/mainThreadEditorsTracker.ts
@@ -14,19 +14,19 @@ import {RunOnceScheduler} from 'vs/base/common/async';
 import {IdGenerator} from 'vs/base/common/idGenerator';
 import {Range} from 'vs/editor/common/core/range';
 import {Selection} from 'vs/editor/common/core/selection';
-import {EndOfLine} from 'vs/workbench/api/node/extHostTypes';
+import {EndOfLine, TextEditorLineNumbersStyle} from 'vs/workbench/api/node/extHostTypes';
 
 export interface ITextEditorConfigurationUpdate {
 	tabSize?: number | string;
 	insertSpaces?: boolean | string;
 	cursorStyle?: EditorCommon.TextEditorCursorStyle;
-	lineNumbers?: boolean | 'relative';
+	lineNumbers?: TextEditorLineNumbersStyle;
 }
 export interface IResolvedTextEditorConfiguration {
 	tabSize: number;
 	insertSpaces: boolean;
 	cursorStyle: EditorCommon.TextEditorCursorStyle;
-	lineNumbers: boolean | 'relative';
+	lineNumbers: TextEditorLineNumbersStyle;
 }
 
 function configurationsEqual(a:IResolvedTextEditorConfiguration, b:IResolvedTextEditorConfiguration) {
@@ -263,8 +263,19 @@ export class MainThreadTextEditor {
 				return;
 			}
 
+			let lineNumbers: true | false | 'relative';
+			switch (newConfiguration.lineNumbers) {
+				case TextEditorLineNumbersStyle.On:
+					lineNumbers = true;
+					break;
+				case TextEditorLineNumbersStyle.Relative:
+					lineNumbers = 'relative';
+					break;
+				default:
+					lineNumbers = false;
+			}
 			this._codeEditor.updateOptions({
-				lineNumbers: newConfiguration.lineNumbers
+				lineNumbers: lineNumbers
 			});
 		}
 	}
@@ -299,17 +310,17 @@ export class MainThreadTextEditor {
 			return this._configuration;
 		}
 		let cursorStyle = this._configuration ? this._configuration.cursorStyle : EditorCommon.TextEditorCursorStyle.Line;
-		let lineNumbers: boolean | 'relative' = this._configuration ? this._configuration.lineNumbers : true;
+		let lineNumbers: TextEditorLineNumbersStyle = this._configuration ? this._configuration.lineNumbers : TextEditorLineNumbersStyle.On;
 		if (codeEditor) {
 			let codeEditorOpts = codeEditor.getConfiguration();
 			cursorStyle = codeEditorOpts.viewInfo.cursorStyle;
 
 			if (codeEditorOpts.viewInfo.renderRelativeLineNumbers) {
-				lineNumbers = 'relative';
+				lineNumbers = TextEditorLineNumbersStyle.Relative;
 			} else if (codeEditorOpts.viewInfo.renderLineNumbers) {
-				lineNumbers = true;
+				lineNumbers = TextEditorLineNumbersStyle.On;
 			} else {
-				lineNumbers = false;
+				lineNumbers = TextEditorLineNumbersStyle.Off;
 			}
 		}