diff --git a/src/worker.js b/src/worker.ts
similarity index 88%
rename from src/worker.js
rename to src/worker.ts
index 3efa141..71fc023 100644
--- a/src/worker.js
+++ b/src/worker.ts
@@ -4,5 +4,5 @@ import { JSONPathEnvironment } from "json-p3";
 const useExtendedSyntax = workerData?.useExtendedSyntax ?? false;
 const env = new JSONPathEnvironment({ strict: !useExtendedSyntax });
 const result = env.query(workerData.expression, workerData.input);
-parentPort.postMessage(result.values());
+parentPort?.postMessage(result.values());
 process.exit();