diff --git a/include/boost/format/alt_sstream.hpp b/include/boost/format/alt_sstream.hpp
index 3a0a07a1..b9a8326d 100644
--- a/include/boost/format/alt_sstream.hpp
+++ b/include/boost/format/alt_sstream.hpp
@@ -138,6 +138,7 @@ namespace boost {
             typedef basic_altstringbuf<Ch, Tr, Alloc>   stringbuf_t;
         public:
             typedef Alloc  allocator_type;
+            ~basic_oaltstringstream() noexcept override = default;
             basic_oaltstringstream() 
                 : pbase_type(new stringbuf_t), stream_t(pbase_type::member.get())
                 { }