diff --git a/include/boost/lexical_cast.hpp b/include/boost/lexical_cast.hpp
index fb76d29..c2580ec 100644
--- a/include/boost/lexical_cast.hpp
+++ b/include/boost/lexical_cast.hpp
@@ -1322,7 +1322,8 @@ namespace boost {
             {   using namespace std;
                 if (put_inf_nan(begin, end, val)) return true;
                 end = begin;
-                end += sprintf(begin,"%.*g", static_cast<int>(boost::detail::lcast_get_precision<float>()), val);
+                const double val_as_double = val;
+                end += sprintf(begin,"%.*g", static_cast<int>(boost::detail::lcast_get_precision<float>()), val_as_double);
                 return end > begin;
             }
 
@@ -1330,7 +1331,7 @@ namespace boost {
             {   using namespace std;
                 if (put_inf_nan(begin, end, val)) return true;
                 end = begin;
-                end += sprintf(begin,"%.*lg", static_cast<int>(boost::detail::lcast_get_precision<double>()), val);
+                end += sprintf(begin,"%.*g", static_cast<int>(boost::detail::lcast_get_precision<double>()), val);
                 return end > begin;
             }
 
@@ -1353,8 +1354,11 @@ namespace boost {
             static bool shl_real_type(float val, wchar_t* begin, wchar_t*& end)
             {   using namespace std;
                 if (put_inf_nan(begin, end, val)) return true;
+                const double val_as_double = val;
                 end = begin + swprintf(begin, end-begin,
-                                          L"%.*g", static_cast<int>(boost::detail::lcast_get_precision<float >()), val );
+                                       L"%.*g",
+                                       static_cast<int>(boost::detail::lcast_get_precision<float >()),
+                                       val_as_double );
                 return end > begin;
             }
 
@@ -1362,7 +1366,7 @@ namespace boost {
             {   using namespace std;
                 if (put_inf_nan(begin, end, val)) return true;
                 end = begin + swprintf(begin, end-begin,
-                                          L"%.*lg", static_cast<int>(boost::detail::lcast_get_precision<double >()), val );
+                                          L"%.*g", static_cast<int>(boost::detail::lcast_get_precision<double >()), val );
                 return end > begin;
             }
 
diff --git a/test/implicit_cast.cpp b/test/implicit_cast.cpp
index e18e17a..8c3bc52 100644
--- a/test/implicit_cast.cpp
+++ b/test/implicit_cast.cpp
@@ -28,5 +28,11 @@ int main()
 
     type<foo> f = check_return(boost::implicit_cast<foo>("hello"));
     type<long> z = check_return(boost::implicit_cast<long>(foo("hello")));
+    
+    // warning supression:
+    (void)x;
+    (void)f;
+    (void)z;
+
     return boost::report_errors();
 }