diff --git a/test/ref_ct_test.cpp b/test/ref_ct_test.cpp
index 7e97957..9e5bf31 100644
--- a/test/ref_ct_test.cpp
+++ b/test/ref_ct_test.cpp
@@ -21,10 +21,16 @@ void ref_test(boost::reference_wrapper<U>)
     BOOST_STATIC_ASSERT((boost::core::is_same<T,type>::value));
 }
 
+template< typename T >
+void assignable_test_(T x1, T x2)
+{
+    x1 = x2;
+}
+
 template< typename T >
 void assignable_test(T x)
 {
-    x = x;
+    assignable_test_( x, x );
 }
 
 template< bool R, typename T >