diff --git a/extensions/css-language-features/client/src/cssClient.ts b/extensions/css-language-features/client/src/cssClient.ts
index f6e8fe3513e..4e90b3482e4 100644
--- a/extensions/css-language-features/client/src/cssClient.ts
+++ b/extensions/css-language-features/client/src/cssClient.ts
@@ -15,7 +15,7 @@ namespace CustomDataChangedNotification {
 export type LanguageClientConstructor = (name: string, description: string, clientOptions: LanguageClientOptions) => BaseLanguageClient;
 
 export interface Runtime {
-	TextDecoder: { new(encoding?: string): { decode(buffer: ArrayBuffer): string } };
+	TextDecoder: typeof TextDecoder;
 	fs?: RequestService;
 }