diff --git a/include/boost/config/platform/hpux.hpp b/include/boost/config/platform/hpux.hpp
index 879fa00b..57566b70 100644
--- a/include/boost/config/platform/hpux.hpp
+++ b/include/boost/config/platform/hpux.hpp
@@ -35,6 +35,8 @@
 #     define BOOST_HAS_THREADS
 #     define BOOST_HAS_PTHREADS
 #  endif
+#elif defined(__HP_aCC) && !defined(BOOST_DISABLE_THREADS)
+#  define BOOST_HAS_PTHREADS
 #endif
 
 // boilerplate code:
@@ -80,3 +82,4 @@
 #endif
 
 
+