diff --git a/lisp/term/pc-win.el b/lisp/term/pc-win.el
index c18636e2f97..5f50acec5cf 100644
--- a/lisp/term/pc-win.el
+++ b/lisp/term/pc-win.el
@@ -214,8 +214,10 @@ support other types of selections."
 ;; it, no matter which variety they've asked for.
 (defun x-frob-font-slant (font which)
   font)
+(make-obsolete 'x-frob-font-slant 'make-face-... "21.1")
 (defun x-frob-font-weight (font which)
   font)
+(make-obsolete 'x-frob-font-weight 'make-face-... "21.1")
 (defun x-font-family-list ()
   "Return a list of available font families on FRAME.\n\
 If FRAME is omitted or nil, use the selected frame.\n\