diff --git a/src/task_queue.hpp b/src/task_queue.hpp
index 358fb33..312b4fa 100644
--- a/src/task_queue.hpp
+++ b/src/task_queue.hpp
@@ -51,7 +51,9 @@ struct task_queue {
 
   auto
   request_shutdown() {
+    std::unique_lock tq_lock(mtx);
     stop = true;
+    tq_lock.unlock();
     cv.notify_all();
   }
 };