--- a/boost/function/function_template.hpp
+++ b/boost/function/function_template.hpp
@@ -895,7 +895,7 @@ namespace boost {
       if (!f.empty()) {
         this->vtable = f.vtable;
         if (this->has_trivial_copy_and_destroy())
-          this->functor = f.functor;
+          std::memcpy(this->functor.data, f.functor.data, sizeof(boost::detail::function::function_buffer));
         else
           get_vtable()->base.manager(f.functor, this->functor,
                                      boost::detail::function::clone_functor_tag);
@@ -983,7 +983,7 @@ namespace boost {
         if (!f.empty()) {
           this->vtable = f.vtable;
           if (this->has_trivial_copy_and_destroy())
-            this->functor = f.functor;
+            std::memcpy(this->functor.data, f.functor.data, sizeof(boost::detail::function::function_buffer));
           else
             get_vtable()->base.manager(f.functor, this->functor,
                                      boost::detail::function::move_functor_tag);