diff --git a/include/boost/config/compiler/sunpro_cc.hpp b/include/boost/config/compiler/sunpro_cc.hpp
index f5184887..a636aa1e 100644
--- a/include/boost/config/compiler/sunpro_cc.hpp
+++ b/include/boost/config/compiler/sunpro_cc.hpp
@@ -69,6 +69,16 @@
 #      define BOOST_NO_IS_ABSTRACT
 #    endif
 
+#    if (__SUNPRO_CC <= 0x5100)
+       // Sun 5.10 may not correctly value-initialize objects of
+       // some user defined types, as was reported in April 2010
+       // (CR 6947016), and confirmed by Steve Clamage.
+       // (Niels Dekker, LKEB, May 2010).
+#      define BOOST_NO_COMPLETE_VALUE_INITIALIZATION
+#    endif
+
+
+
 //
 // Issues that effect all known versions:
 //