diff --git a/include/crt/sec_api/string_s.h b/include/crt/sec_api/string_s.h
index 9db70e77d50..4a1c00159ee 100644
--- a/include/crt/sec_api/string_s.h
+++ b/include/crt/sec_api/string_s.h
@@ -21,6 +21,9 @@ extern "C" {
   _CRTIMP errno_t __cdecl _strnset_s(char *_Str,size_t _Size,int _Val,size_t _MaxCount);
   _CRTIMP errno_t __cdecl _strupr_s(char *_Str,size_t _Size);
   _CRTIMP errno_t __cdecl _strupr_s_l(char *_Str,size_t _Size,_locale_t _Locale);
+  _CRTIMP errno_t __cdecl strcpy_s(char *_Dst, size_t _Size, const char *_Src);
+  _CRTIMP errno_t __cdecl strcat_s(char *_Dst, size_t _Size, const char *_Src);
+
 #ifndef _WSTRING_S_DEFINED
 #define _WSTRING_S_DEFINED
   _CRTIMP wchar_t *__cdecl wcstok_s(wchar_t *_Str,const wchar_t *_Delim,wchar_t **_Context);