diff --git a/src/proto/os_mswin.pro b/src/proto/os_mswin.pro
index 752a27b..2bf927d 100644
--- a/src/proto/os_mswin.pro
+++ b/src/proto/os_mswin.pro
@@ -22,14 +22,14 @@
 int can_end_termcap_mode __ARGS((int give_msg));
 int mch_screenmode __ARGS((char_u *arg));
 int mch_libcall __ARGS((char_u *libname, char_u *funcname, char_u *argstring, int argint, char_u **string_result, int *number_result));
-int utf8_to_ucs2 __ARGS((char_u *instr, int inlen, short_u *outstr, int *unconvlenp));
-int ucs2_to_utf8 __ARGS((short_u *instr, int inlen, char_u *outstr));
+int utf8_to_utf16 __ARGS((char_u *instr, int inlen, short_u *outstr, int *unconvlenp));
+int utf16_to_utf8 __ARGS((short_u *instr, int inlen, char_u *outstr));
 void MultiByteToWideChar_alloc __ARGS((UINT cp, DWORD flags, LPCSTR in, int inlen, LPWSTR *out, int *outlen));
 void WideCharToMultiByte_alloc __ARGS((UINT cp, DWORD flags, LPCWSTR in, int inlen, LPSTR *out, int *outlen, LPCSTR def, LPBOOL useddef));
 int clip_mch_own_selection __ARGS((VimClipboard *cbd));
 void clip_mch_lose_selection __ARGS((VimClipboard *cbd));
-short_u *enc_to_ucs2 __ARGS((char_u *str, int *lenp));
-char_u *ucs2_to_enc __ARGS((short_u *str, int *lenp));
+short_u *enc_to_utf16 __ARGS((char_u *str, int *lenp));
+char_u *utf16_to_enc __ARGS((short_u *str, int *lenp));
 void clip_mch_request_selection __ARGS((VimClipboard *cbd));
 void acp_to_enc __ARGS((char_u *str, int str_size, char_u **out, int *outlen));
 void clip_mch_set_selection __ARGS((VimClipboard *cbd));