diff --git a/include/boost/system/system_error.hpp b/include/boost/system/system_error.hpp
index 116fd38..ef19e97 100644
--- a/include/boost/system/system_error.hpp
+++ b/include/boost/system/system_error.hpp
@@ -47,7 +47,7 @@ namespace boost
       virtual ~system_error() BOOST_NOEXCEPT_OR_NOTHROW {}
 
       error_code code() const BOOST_NOEXCEPT { return m_error_code; }
-      const char * what() const BOOST_NOEXCEPT_OR_NOTHROW;
+      const char * what() const BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE;
 
     private:
       error_code           m_error_code;
diff --git a/test/warnings_test.cpp b/test/warnings_test.cpp
index 39c6f7a..7876815 100644
--- a/test/warnings_test.cpp
+++ b/test/warnings_test.cpp
@@ -18,6 +18,7 @@
 #pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
 #endif
 
+#include <boost/system/system_error.hpp>
 #include <boost/system/error_code.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <cerrno>
@@ -42,5 +43,10 @@ int main()
 
     BOOST_TEST( bc == bn );
 
+    boost::system::system_error x( bc, "what_arg" );
+
+    BOOST_TEST_EQ( x.code(), bc );
+    BOOST_TEST_CSTR_EQ( x.what(), "what_arg" );
+
     return boost::report_errors();
 }