diff --git a/include/boost/math/tools/config.hpp b/include/boost/math/tools/config.hpp
index 4ec5768aa..23cba0c9a 100644
--- a/include/boost/math/tools/config.hpp
+++ b/include/boost/math/tools/config.hpp
@@ -50,6 +50,10 @@
 // are disabled for now.  (JM 2012).
 #  define BOOST_MATH_NO_REAL_CONCEPT_TESTS
 #endif
+#ifdef sun
+// Any use of __float128 in program startup code causes a segfault  (tested JM 2015, Solaris 11).
+#  define BOOST_MATH_DISABLE_FLOAT128
+#endif
 #if (defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)) && ((LDBL_MANT_DIG == 106) || (__LDBL_MANT_DIG__ == 106)) && !defined(BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS)
 //
 // Darwin's rather strange "double double" is rather hard to