diff --git a/src/util/ThreadUtil.h b/src/util/ThreadUtil.h
index 0ef29fe..eaa6055 100755
--- a/src/util/ThreadUtil.h
+++ b/src/util/ThreadUtil.h
@@ -8,8 +8,8 @@ class AtomicWrapper
 {
 private:
 
-	T* data;
-	std::mutex* mtx;
+	mutable T* data;
+	mutable std::mutex* mtx;
 public:
 
 	T& operator*()