diff --git a/src/win32/thread.cpp b/src/win32/thread.cpp
index 7bdce652..b9434621 100644
--- a/src/win32/thread.cpp
+++ b/src/win32/thread.cpp
@@ -67,7 +67,7 @@ namespace boost
                 boost::throw_exception(thread_resource_error());
         }
 
-#ifdef BOOST_NO_THREADEX
+#ifndef BOOST_HAS_THREADEX
 // Windows CE doesn't define _beginthreadex
 
         struct ThreadProxyData