diff --git a/source/mijin/async/task_mutex.hpp b/source/mijin/async/task_mutex.hpp
index ce2a9c3..89d2a41 100644
--- a/source/mijin/async/task_mutex.hpp
+++ b/source/mijin/async/task_mutex.hpp
@@ -37,6 +37,7 @@ public:
         locked_ = true;
         co_return TaskMutexLock(this);
     }
+    [[nodiscard]] inline bool isLocked() const noexcept { return locked_; }
 
     friend class TaskMutexLock;
 };