diff --git a/src/vs/workbench/contrib/webview/browser/dynamicWebviewEditorOverlay.ts b/src/vs/workbench/contrib/webview/browser/dynamicWebviewEditorOverlay.ts
index 31f778e3bfc5ede14e070fb0d05936b9c38ce0a6..cceb1698cf434d8bc577041a4a086b5724f31f5d 100644
--- a/src/vs/workbench/contrib/webview/browser/dynamicWebviewEditorOverlay.ts
+++ b/src/vs/workbench/contrib/webview/browser/dynamicWebviewEditorOverlay.ts
@@ -8,7 +8,7 @@ import { Emitter, Event } from 'vs/base/common/event';
 import { Disposable, DisposableStore, MutableDisposable, toDisposable } from 'vs/base/common/lifecycle';
 import { URI } from 'vs/base/common/uri';
 import { ExtensionIdentifier } from 'vs/platform/extensions/common/extensions';
-import { IWebviewService, Webview, WebviewContentOptions, WebviewEditorOverlay, WebviewElement, WebviewOptions } from 'vs/workbench/contrib/webview/browser/webview';
+import { IWebviewService, Webview, WebviewContentOptions, WebviewEditorOverlay, WebviewElement, WebviewOptions, WebviewExtensionDescription } from 'vs/workbench/contrib/webview/browser/webview';
 import { IWorkbenchLayoutService, Parts } from 'vs/workbench/services/layout/browser/layoutService';
 import { Dimension } from 'vs/base/browser/dom';
 import { assertIsDefined } from 'vs/base/common/types';
@@ -25,10 +25,7 @@ export class DynamicWebviewEditorOverlay extends Disposable implements WebviewEd
 	private _html: string = '';
 	private _initialScrollProgress: number = 0;
 	private _state: string | undefined = undefined;
-	private _extension: {
-		readonly location: URI;
-		readonly id?: ExtensionIdentifier;
-	} | undefined;
+	private _extension: WebviewExtensionDescription | undefined;
 
 	private _owner: any = undefined;
 
diff --git a/src/vs/workbench/contrib/webview/browser/webview.ts b/src/vs/workbench/contrib/webview/browser/webview.ts
index 083550bf21d086f701a94a8bac2e00b1b990dfe7..0cb185a5b0e52c39186de7bd64f0790ec2d64bde 100644
--- a/src/vs/workbench/contrib/webview/browser/webview.ts
+++ b/src/vs/workbench/contrib/webview/browser/webview.ts
@@ -54,14 +54,16 @@ export interface WebviewContentOptions {
 	readonly enableCommandUris?: boolean;
 }
 
+export interface WebviewExtensionDescription {
+	readonly location: URI;
+	readonly id: ExtensionIdentifier;
+}
+
 export interface Webview extends IDisposable {
 
 	html: string;
 	contentOptions: WebviewContentOptions;
-	extension: {
-		readonly location: URI;
-		readonly id?: ExtensionIdentifier;
-	} | undefined;
+	extension: WebviewExtensionDescription | undefined;
 	initialScrollProgress: number;
 	state: string | undefined;
 
diff --git a/src/vs/workbench/contrib/webview/browser/webviewElement.ts b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
index a80e6b551c03e62c9cfb1fafe544f4fde179abd2..e33c746b373fb56a1607fe4a0b681fa12dd97a77 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
@@ -12,7 +12,7 @@ import { IConfigurationService } from 'vs/platform/configuration/common/configur
 import { ExtensionIdentifier } from 'vs/platform/extensions/common/extensions';
 import { IFileService } from 'vs/platform/files/common/files';
 import { ITunnelService } from 'vs/platform/remote/common/tunnel';
-import { Webview, WebviewContentOptions, WebviewOptions } from 'vs/workbench/contrib/webview/browser/webview';
+import { Webview, WebviewContentOptions, WebviewOptions, WebviewExtensionDescription } from 'vs/workbench/contrib/webview/browser/webview';
 import { areWebviewInputOptionsEqual } from 'vs/workbench/contrib/webview/browser/webviewWorkbenchService';
 import { WebviewPortMappingManager } from 'vs/workbench/contrib/webview/common/portMapping';
 import { loadLocalResource } from 'vs/workbench/contrib/webview/common/resourceLoader';
@@ -35,10 +35,7 @@ export class IFrameWebview extends Disposable implements Webview {
 
 	private readonly _portMappingManager: WebviewPortMappingManager;
 
-	public extension: {
-		readonly location: URI;
-		readonly id?: ExtensionIdentifier;
-	} | undefined;
+	public extension: WebviewExtensionDescription | undefined;
 
 	constructor(
 		private readonly id: string,
diff --git a/src/vs/workbench/contrib/webview/browser/webviewWorkbenchService.ts b/src/vs/workbench/contrib/webview/browser/webviewWorkbenchService.ts
index c0e1994c2064cc006b808c20f508dedb6b3be452..e5b66c969904234b700a5eb029e49c6bc5bfb541 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewWorkbenchService.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewWorkbenchService.ts
@@ -15,7 +15,7 @@ import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
 import { IWorkspaceContextService } from 'vs/platform/workspace/common/workspace';
 import { GroupIdentifier } from 'vs/workbench/common/editor';
-import { IWebviewService, WebviewContentOptions, WebviewEditorOverlay, WebviewOptions } from 'vs/workbench/contrib/webview/browser/webview';
+import { IWebviewService, WebviewContentOptions, WebviewEditorOverlay, WebviewOptions, WebviewExtensionDescription } from 'vs/workbench/contrib/webview/browser/webview';
 import { IEditorGroup, IEditorGroupsService } from 'vs/workbench/services/editor/common/editorGroupsService';
 import { ACTIVE_GROUP_TYPE, IEditorService, SIDE_GROUP_TYPE } from 'vs/workbench/services/editor/common/editorService';
 import { WebviewInput } from './webviewEditorInput';
@@ -44,11 +44,6 @@ export function areWebviewInputOptionsEqual(a: WebviewInputOptions, b: WebviewIn
 		&& equals(a.portMapping, b.portMapping, (a, b) => a.extensionHostPort === b.extensionHostPort && a.webviewPort === b.webviewPort);
 }
 
-export interface WebviewExtensionDescription {
-	readonly location: URI;
-	readonly id: ExtensionIdentifier;
-}
-
 export interface IWebviewWorkbenchService {
 	_serviceBrand: undefined;
 
diff --git a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
index 9cd4185fd76cc8bf7160586dffb24c638fdf7ecf..01639181a38f51c05df214a4162b24ae179ba80b 100644
--- a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
@@ -18,7 +18,7 @@ import { IInstantiationService } from 'vs/platform/instantiation/common/instanti
 import { ITunnelService } from 'vs/platform/remote/common/tunnel';
 import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
 import { IThemeService } from 'vs/platform/theme/common/themeService';
-import { Webview, WebviewContentOptions, WebviewOptions } from 'vs/workbench/contrib/webview/browser/webview';
+import { Webview, WebviewContentOptions, WebviewOptions, WebviewExtensionDescription } from 'vs/workbench/contrib/webview/browser/webview';
 import { WebviewPortMappingManager } from 'vs/workbench/contrib/webview/common/portMapping';
 import { WebviewResourceScheme } from 'vs/workbench/contrib/webview/common/resourceLoader';
 import { WebviewThemeDataProvider } from 'vs/workbench/contrib/webview/common/themeing';
@@ -247,10 +247,7 @@ export class ElectronWebviewBasedWebview extends Disposable implements Webview,
 	private readonly _onDidFocus = this._register(new Emitter<void>());
 	public readonly onDidFocus: Event<void> = this._onDidFocus.event;
 
-	public extension: {
-		readonly location: URI;
-		readonly id?: ExtensionIdentifier;
-	} | undefined;
+	public extension: WebviewExtensionDescription | undefined;
 
 	constructor(
 		options: WebviewOptions,