diff --git a/include/boost/lexical_cast.hpp b/include/boost/lexical_cast.hpp
index 37d4fb4..25b7f61 100644
--- a/include/boost/lexical_cast.hpp
+++ b/include/boost/lexical_cast.hpp
@@ -1446,7 +1446,7 @@ namespace boost {
             }
 
             template <class T, class SomeCharT>
-            bool shl_real_type(const T& val, SomeCharT* begin, SomeCharT*& end) {
+            bool shl_real_type(const T& val, SomeCharT* /*begin*/, SomeCharT*& /*end*/) {
                 lcast_set_precision(out_stream, &val);
                 return shl_input_streamable(val);
             }