diff --git a/src/vs/workbench/contrib/webview/browser/webviewElement.ts b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
index f64f439ece05d0afbeb4aafe8651f41aa5d3e8a8..1d82afae00611468eac332460acfe2456c3fe33b 100644
--- a/src/vs/workbench/contrib/webview/browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/browser/webviewElement.ts
@@ -172,7 +172,8 @@ export class IFrameWebview extends Disposable implements Webview {
 	}
 
 	private preprocessHtml(value: string): string {
-		return value.replace(/(?<=["'])vscode-resource:([^\s'"]+)(?=["'])/gi, `${this.environmentService.webviewEndpoint}/vscode-resource$1`);
+		return value.replace(/(["'])vscode-resource:([^\s'"]+?)(["'])/gi, (_, startQuote, path, endQuote) =>
+			`${startQuote}${this.environmentService.webviewEndpoint}/vscode-resource${path}${endQuote}`);
 	}
 
 	public update(html: string, options: WebviewContentOptions, retainContextWhenHidden: boolean) {