diff --git a/src/vs/vscode.d.ts b/src/vs/vscode.d.ts
index c419713c90a..b7c67664cb7 100644
--- a/src/vs/vscode.d.ts
+++ b/src/vs/vscode.d.ts
@@ -101,7 +101,9 @@ declare module 'vscode' {
 		readonly fileName: string;
 
 		/**
-		 * Is this document representing an untitled file.
+		 * Is this document representing an untitled file which has never been saved yet. *Note* that
+		 * this does not mean the document will be saved to disk, use [`uri.scheme`](#Uri.scheme)
+		 * to figure out where a document will be [saved](#FileSystemProvider), e.g. `file`, `ftp` etc.
 		 */
 		readonly isUntitled: boolean;
 
diff --git a/src/vs/workbench/api/node/extHostDocumentData.ts b/src/vs/workbench/api/node/extHostDocumentData.ts
index d42afcf7ba0..2eeef2a7d5f 100644
--- a/src/vs/workbench/api/node/extHostDocumentData.ts
+++ b/src/vs/workbench/api/node/extHostDocumentData.ts
@@ -13,6 +13,7 @@ import * as vscode from 'vscode';
 import { getWordAtText, ensureValidWordDefinition } from 'vs/editor/common/model/wordHelper';
 import { MainThreadDocumentsShape } from './extHost.protocol';
 import { TPromise } from 'vs/base/common/winjs.base';
+import { Schemas } from 'vs/base/common/network';
 
 const _modeId2WordDefinition = new Map<string, RegExp>();
 export function setWordDefinitionFor(modeId: string, wordDefinition: RegExp): void {
@@ -68,8 +69,7 @@ export class ExtHostDocumentData extends MirrorTextModel {
 			this._document = {
 				get uri() { return data._uri; },
 				get fileName() { return data._uri.fsPath; },
-				// todo@remote -> https://github.com/Microsoft/vscode/issues/48269
-				get isUntitled() { return data._uri.scheme !== 'file'; },
+				get isUntitled() { return data._uri.scheme === Schemas.untitled; },
 				get languageId() { return data._languageId; },
 				get version() { return data._versionId; },
 				get isClosed() { return data._isDisposed; },