diff --git a/include/ostream b/include/ostream
index ee220f3..14b49d7 100644
--- a/include/ostream
+++ b/include/ostream
@@ -130,6 +130,35 @@
 template <class Stream, class T>
   Stream&& operator<<(Stream&& os, const T& x);
 
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, wchar_t) = delete;               // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, char8_t) = delete;               // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, char16_t) = delete;              // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, char32_t) = delete;              // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, char8_t) = delete;         // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, char16_t) = delete;        // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, char32_t) = delete;        // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, const wchar_t*) = delete;        // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, const char8_t*) = delete;        // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, const char16_t*) = delete;       // since C++20
+template<class traits>
+basic_ostream<char, traits>& operator<<(basic_ostream<char, traits>&, const char32_t*) = delete;       // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, const char8_t*) = delete;  // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, const char16_t*) = delete; // since C++20
+template<class traits>
+basic_ostream<wchar_t, traits>& operator<<(basic_ostream<wchar_t, traits>&, const char32_t*) = delete; // since C++20
+
 }  // std
 
 */
@@ -1102,6 +1131,57 @@
                          use_facet<ctype<_CharT> >(__os.getloc()).widen('1'));
 }
 
+#if _LIBCPP_STD_VER > 17
+
+#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, wchar_t) = delete;
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const wchar_t*) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char16_t) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char32_t) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char16_t*) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char32_t*) = delete;
+
+#endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
+
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char8_t) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char8_t) = delete;
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char8_t*) = delete;
+
+template <class _Traits>
+basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char8_t*) = delete;
+#endif
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char16_t) = delete;
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char32_t) = delete;
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char16_t*) = delete;
+
+template <class _Traits>
+basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char32_t*) = delete;
+
+#endif // _LIBCPP_STD_VER > 17
+
 extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ostream<char>;
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ostream<wchar_t>;