diff --git a/packages/typescript-language-service/src/services/inlayHints.ts b/packages/typescript-language-service/src/services/inlayHints.ts
index 6fc6d7b35..8036f2aa0 100644
--- a/packages/typescript-language-service/src/services/inlayHints.ts
+++ b/packages/typescript-language-service/src/services/inlayHints.ts
@@ -19,7 +19,7 @@ export function register(
 		const fileName = shared.uriToFsPath(document.uri);
 		const start = document.offsetAt(range.start);
 		const end = document.offsetAt(range.end);
-		const inlayHints = languageService.provideInlayHints(fileName, { start, length: end - start }, preferences);
+		const inlayHints = 'provideInlayHints' in languageService ? languageService.provideInlayHints(fileName, { start, length: end - start }, preferences) : [];
 
 		return inlayHints.map(inlayHint => {
 			const result = vscode.InlayHint.create(