diff --git a/include/boost/type_traits/is_convertible.hpp b/include/boost/type_traits/is_convertible.hpp
index 88a8ccf..517d1cf 100644
--- a/include/boost/type_traits/is_convertible.hpp
+++ b/include/boost/type_traits/is_convertible.hpp
@@ -125,7 +125,7 @@ struct is_convertible_basic_impl
 };
 
 #elif (defined(__EDG_VERSION__) && (__EDG_VERSION__ >= 245) && !defined(__ICL)) \
-      || defined(__IBMCPP__)
+      || defined(__IBMCPP__) || defined(__HP_aCC)
 //
 // This is *almost* an ideal world implementation as it doesn't rely
 // on undefined behaviour by passing UDT's through (...).