diff --git a/src/win32/thread.cpp b/src/win32/thread.cpp
index 8e62b9ad..54636dcc 100644
--- a/src/win32/thread.cpp
+++ b/src/win32/thread.cpp
@@ -58,8 +58,7 @@ namespace boost
         void set_current_thread_data(detail::thread_data_base* new_data)
         {
             boost::call_once(current_thread_tls_init_flag,create_current_thread_tls_key);
-            BOOL const res=TlsSetValue(current_thread_tls_key,new_data);
-            BOOST_ASSERT(res);
+            BOOST_VERIFY(TlsSetValue(current_thread_tls_key,new_data));
         }
 #endif