diff --git a/src/vs/workbench/api/electron-browser/mainThreadWebview.ts b/src/vs/workbench/api/electron-browser/mainThreadWebview.ts
index 4f007ab2439..c6411afa704 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadWebview.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadWebview.ts
@@ -177,7 +177,7 @@ export class MainThreadWebviews implements MainThreadWebviewsShape, WebviewReviv
 			onDidClickLink: uri => this.onDidClickLink(handle, uri),
 			onMessage: message => this._proxy.$onMessage(handle, message),
 			onDispose: () => {
-				this._proxy.onDidDisposeWebviewPanel(handle).then(() => {
+				this._proxy.$onDidDisposeWebviewPanel(handle).then(() => {
 					this._webviews.delete(handle);
 				});
 			}
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 38d81ee9141..f18f37f7e78 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -364,7 +364,7 @@ export interface MainThreadWebviewsShape extends IDisposable {
 export interface ExtHostWebviewsShape {
 	$onMessage(handle: WebviewPanelHandle, message: any): void;
 	$onDidChangeWebviewPanelViewState(handle: WebviewPanelHandle, active: boolean, position: EditorPosition): void;
-	onDidDisposeWebviewPanel(handle: WebviewPanelHandle): Thenable<void>;
+	$onDidDisposeWebviewPanel(handle: WebviewPanelHandle): Thenable<void>;
 	$deserializeWebviewPanel(newWebviewHandle: WebviewPanelHandle, viewType: string, title: string, state: any, position: EditorPosition, options: vscode.WebviewOptions): Thenable<void>;
 	$serializeWebviewPanel(webviewHandle: WebviewPanelHandle): Thenable<any>;
 }
diff --git a/src/vs/workbench/api/node/extHostWebview.ts b/src/vs/workbench/api/node/extHostWebview.ts
index 53eb8d31972..a841e091574 100644
--- a/src/vs/workbench/api/node/extHostWebview.ts
+++ b/src/vs/workbench/api/node/extHostWebview.ts
@@ -254,7 +254,7 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		}
 	}
 
-	onDidDisposeWebviewPanel(handle: WebviewPanelHandle): Thenable<void> {
+	$onDidDisposeWebviewPanel(handle: WebviewPanelHandle): Thenable<void> {
 		const panel = this.getWebviewPanel(handle);
 		if (panel) {
 			panel.dispose();