diff --git a/src/vs/workbench/api/browser/mainThreadCustomEditors.ts b/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
index 620922edc5ea3a8230e96317abe2d1c59cb4b999..848f4a142edf7f47bb4f72418fe38438873cf906 100644
--- a/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
+++ b/src/vs/workbench/api/browser/mainThreadCustomEditors.ts
@@ -333,7 +333,7 @@ class MainThreadCustomEditorModel extends Disposable implements ICustomEditorMod
 	}
 
 	public get capabilities(): WorkingCopyCapabilities {
-		return 0;
+		return WorkingCopyCapabilities.None;
 	}
 
 	public isDirty(): boolean {
diff --git a/src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts b/src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts
index a0e064a2aec8f671036deb3d10ed52a61b4bacbe..9ef0ab0a5ffc769747b7f2d34ecdc9762fa794e8 100644
--- a/src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts
+++ b/src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts
@@ -84,7 +84,7 @@ export class NotebookEditorModel extends EditorModel implements IWorkingCopy, IN
 		this._register(this._workingCopyService.registerWorkingCopy(workingCopyAdapter));
 	}
 
-	capabilities = 0;
+	capabilities = WorkingCopyCapabilities.None;
 
 	async backup(): Promise<IWorkingCopyBackup<NotebookDocumentBackupData>> {
 		if (this._notebook.supportBackup) {
diff --git a/src/vs/workbench/contrib/searchEditor/browser/searchEditorInput.ts b/src/vs/workbench/contrib/searchEditor/browser/searchEditorInput.ts
index c884a84be2be89d27a6d0ad612b870e3e144809d..da6858a833e13ae7958b1736628b877fc0d4e018 100644
--- a/src/vs/workbench/contrib/searchEditor/browser/searchEditorInput.ts
+++ b/src/vs/workbench/contrib/searchEditor/browser/searchEditorInput.ts
@@ -112,7 +112,7 @@ export class SearchEditorInput extends EditorInput {
 		const workingCopyAdapter = new class implements IWorkingCopy {
 			readonly resource = input.modelUri;
 			get name() { return input.getName(); }
-			readonly capabilities = input.isUntitled() ? WorkingCopyCapabilities.Untitled : 0;
+			readonly capabilities = input.isUntitled() ? WorkingCopyCapabilities.Untitled : WorkingCopyCapabilities.None;
 			readonly onDidChangeDirty = input.onDidChangeDirty;
 			readonly onDidChangeContent = input.onDidChangeContent;
 			isDirty(): boolean { return input.isDirty(); }
diff --git a/src/vs/workbench/services/textfile/common/textFileEditorModel.ts b/src/vs/workbench/services/textfile/common/textFileEditorModel.ts
index 1bb7ac6975d25c57fd15c2f1972a14c1278e7056..721d459f8d4870bf5031581c449760d2bac31e7a 100644
--- a/src/vs/workbench/services/textfile/common/textFileEditorModel.ts
+++ b/src/vs/workbench/services/textfile/common/textFileEditorModel.ts
@@ -19,7 +19,7 @@ import { ITextBufferFactory, ITextModel } from 'vs/editor/common/model';
 import { INotificationService } from 'vs/platform/notification/common/notification';
 import { ILogService } from 'vs/platform/log/common/log';
 import { basename } from 'vs/base/common/path';
-import { IWorkingCopyService, IWorkingCopyBackup } from 'vs/workbench/services/workingCopy/common/workingCopyService';
+import { IWorkingCopyService, IWorkingCopyBackup, WorkingCopyCapabilities } from 'vs/workbench/services/workingCopy/common/workingCopyService';
 import { IFilesConfigurationService } from 'vs/workbench/services/filesConfiguration/common/filesConfigurationService';
 import { ILabelService } from 'vs/platform/label/common/label';
 import { CancellationTokenSource } from 'vs/base/common/cancellation';
@@ -65,7 +65,7 @@ export class TextFileEditorModel extends BaseTextEditorModel implements ITextFil
 
 	//#endregion
 
-	readonly capabilities = 0;
+	readonly capabilities = WorkingCopyCapabilities.None;
 
 	readonly name = basename(this.labelService.getUriLabel(this.resource));
 
diff --git a/src/vs/workbench/services/workingCopy/common/workingCopyService.ts b/src/vs/workbench/services/workingCopy/common/workingCopyService.ts
index ba56c701fece50488d551a0d66a7340aa2437081..e5f96509de823cd2bad255465f36e232e1e6bed5 100644
--- a/src/vs/workbench/services/workingCopy/common/workingCopyService.ts
+++ b/src/vs/workbench/services/workingCopy/common/workingCopyService.ts
@@ -14,6 +14,11 @@ import { ITextSnapshot } from 'vs/editor/common/model';
 
 export const enum WorkingCopyCapabilities {
 
+	/**
+	 * Signals no specific capability for the working copy.
+	 */
+	None = 0,
+
 	/**
 	 * Signals that the working copy requires
 	 * additional input when saving, e.g. an
diff --git a/src/vs/workbench/services/workingCopy/test/common/workingCopyService.test.ts b/src/vs/workbench/services/workingCopy/test/common/workingCopyService.test.ts
index 50fbeff1806f587b55b5508886a42fd77cdddf19..97840f97145f888082ccc5bfd96b052948562a8f 100644
--- a/src/vs/workbench/services/workingCopy/test/common/workingCopyService.test.ts
+++ b/src/vs/workbench/services/workingCopy/test/common/workingCopyService.test.ts
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as assert from 'assert';
-import { IWorkingCopy, IWorkingCopyBackup } from 'vs/workbench/services/workingCopy/common/workingCopyService';
+import { IWorkingCopy, IWorkingCopyBackup, WorkingCopyCapabilities } from 'vs/workbench/services/workingCopy/common/workingCopyService';
 import { URI } from 'vs/base/common/uri';
 import { Emitter } from 'vs/base/common/event';
 import { Disposable } from 'vs/base/common/lifecycle';
@@ -23,7 +23,7 @@ export class TestWorkingCopy extends Disposable implements IWorkingCopy {
 	private readonly _onDispose = this._register(new Emitter<void>());
 	readonly onDispose = this._onDispose.event;
 
-	readonly capabilities = 0;
+	readonly capabilities = WorkingCopyCapabilities.None;
 
 	readonly name = basename(this.resource);