diff --git a/include/boost/lexical_cast.hpp b/include/boost/lexical_cast.hpp
index 34a0aed..686b9f5 100644
--- a/include/boost/lexical_cast.hpp
+++ b/include/boost/lexical_cast.hpp
@@ -1750,6 +1750,7 @@ namespace boost
                 } catch( ::boost::numeric::bad_numeric_cast const& ) {
                     BOOST_LCAST_THROW_BAD_CAST(Source, Target);
                 }
+                BOOST_UNREACHABLE_RETURN(static_cast<Target>(0));
             }
         };
 
@@ -1776,6 +1777,7 @@ namespace boost
                 } catch( ::boost::numeric::bad_numeric_cast const& ) {
                     BOOST_LCAST_THROW_BAD_CAST(Source, Target);
                 }
+                BOOST_UNREACHABLE_RETURN(static_cast<Target>(0));
             }
         };