diff --git a/runtime/atomic.h b/runtime/atomic.h
index 5ddafb4..868f32c 100644
--- a/runtime/atomic.h
+++ b/runtime/atomic.h
@@ -256,7 +256,7 @@
 template<typename T>
 class Atomic : public std::atomic<T> {
  public:
-  Atomic<T>() : std::atomic<T>() { }
+  Atomic<T>() : std::atomic<T>(0) { }
 
   explicit Atomic<T>(T value) : std::atomic<T>(value) { }