diff -Naur a/boost/lexical_cast/detail/converter_lexical.hpp b/boost/lexical_cast/detail/converter_lexical.hpp
--- a/boost/lexical_cast/detail/converter_lexical.hpp     2015-09-18 14:22:09.121271000 -0400
+++ b/boost/lexical_cast/detail/converter_lexical.hpp     2015-09-18 14:23:02.371625000 -0400
@@ -364,7 +364,6 @@
 #endif
         };
 
-#ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
         // Helper for floating point types.
         // -1.23456789e-123456
         // ^                   sign
@@ -380,6 +379,7 @@
                 Source, BOOST_DEDUCED_TYPENAME boost::enable_if<boost::is_float<Source> >::type
             >
         {
+#ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
             BOOST_STATIC_ASSERT(
                     std::numeric_limits<Source>::max_exponent10 <=  999999L &&
                     std::numeric_limits<Source>::min_exponent10 >= -999999L
@@ -388,8 +388,10 @@
             BOOST_STATIC_CONSTANT(std::size_t, value =
                     5 + lcast_precision<Source>::value + 6
                 );
-        };
+#else
+            BOOST_STATIC_CONSTANT(std::size_t, value = 156);
 #endif // #ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
+        };
     }
 
     namespace detail // lexical_cast_stream_traits<Source, Target>