diff --git a/include/boost/fiber/future/detail/shared_state.hpp b/include/boost/fiber/future/detail/shared_state.hpp
index 790ee89d..c0dccea1 100644
--- a/include/boost/fiber/future/detail/shared_state.hpp
+++ b/include/boost/fiber/future/detail/shared_state.hpp
@@ -10,6 +10,7 @@
 #include <cstddef>
 
 #include <boost/assert.hpp>
+#include <boost/atomic.hpp>
 #include <boost/config.hpp>
 #include <boost/exception_ptr.hpp>
 #include <boost/intrusive_ptr.hpp>
@@ -36,7 +37,7 @@ template< typename R >
 class shared_state : public noncopyable
 {
 private:
-    std::size_t             use_count_;
+    atomic< std::size_t >   use_count_;
     mutable mutex           mtx_;
     mutable condition       waiters_;
     bool                    ready_;