diff --git a/src/vs/workbench/contrib/webview/browser/webviewEditorService.ts b/src/vs/workbench/contrib/webview/browser/webviewEditorService.ts
index 49d8bcc11cdfcf8cd499a79cda1b926e59b71e56..e81418df66ad1f7341bbf92aa347b4ade412c515 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewEditorService.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewEditorService.ts
@@ -90,7 +90,7 @@ export function areWebviewInputOptionsEqual(a: WebviewInputOptions, b: WebviewIn
 		&& a.retainContextWhenHidden === b.retainContextWhenHidden
 		&& a.tryRestoreScrollPosition === b.tryRestoreScrollPosition
 		&& (a.localResourceRoots === b.localResourceRoots || (Array.isArray(a.localResourceRoots) && Array.isArray(b.localResourceRoots) && equals(a.localResourceRoots, b.localResourceRoots, (a, b) => a.toString() === b.toString())))
-		&& (a.portMappings === b.portMappings || (Array.isArray(a.portMappings) && Array.isArray(b.portMappings) && equals(a.portMappings, b.portMappings, (a, b) => a.extensionHostPort === b.extensionHostPort && a.webviewPort === b.webviewPort)));
+		&& (a.portMapping === b.portMapping || (Array.isArray(a.portMapping) && Array.isArray(b.portMapping) && equals(a.portMapping, b.portMapping, (a, b) => a.extensionHostPort === b.extensionHostPort && a.webviewPort === b.webviewPort)));
 }
 
 function canRevive(reviver: WebviewReviver, webview: WebviewEditorInput): boolean {
diff --git a/src/vs/workbench/contrib/webview/browser/webviewElement.ts b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
index 5e5df2a02cf6b8722aca43ffb1c6723047f6c3e0..aa4473313d4f914e8e06bc5d5a724f329d26fee2 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
@@ -53,7 +53,7 @@ export class IFrameWebview extends Disposable implements Webview {
 
 		this._portMappingManager = this._register(new WebviewPortMappingManager(
 			this._options.extension ? this._options.extension.location : undefined,
-			() => this.content.options.portMappings || [],
+			() => this.content.options.portMapping || [],
 			tunnelService
 		));
 
diff --git a/src/vs/workbench/contrib/webview/common/webview.ts b/src/vs/workbench/contrib/webview/common/webview.ts
index 8d81b487a5a966c31cafe7596007697c3899ef91..d6a73ff5d613160958c2d0527a2251efc89ee9a4 100644
--- a/src/vs/workbench/contrib/webview/common/webview.ts
+++ b/src/vs/workbench/contrib/webview/common/webview.ts
@@ -55,7 +55,7 @@ export interface WebviewContentOptions {
 	readonly allowScripts?: boolean;
 	readonly svgWhiteList?: string[];
 	readonly localResourceRoots?: ReadonlyArray<URI>;
-	readonly portMappings?: ReadonlyArray<modes.IWebviewPortMapping>;
+	readonly portMapping?: ReadonlyArray<modes.IWebviewPortMapping>;
 	readonly enableCommandUris?: boolean;
 }
 
diff --git a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
index e42e1a4b401cb5ae9fd94e4b31ef9ab3c55f9269..3c030feb235441f0603290abde883cb263d23a7e 100644
--- a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
@@ -327,7 +327,7 @@ export class ElectronWebviewBasedWebview extends Disposable implements Webview {
 		this._register(new WebviewPortMappingProvider(
 			session,
 			_options.extension ? _options.extension.location : undefined,
-			() => (this.content.options.portMappings || []),
+			() => (this.content.options.portMapping || []),
 			tunnelService,
 		));