diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index c669d45a0bd..0ffbc915448 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -1338,21 +1338,11 @@ The list is updated automatically by `defun-rcirc-command'.")
   (interactive "zCoding system for incoming messages: ")
   (setq-local rcirc-decode-coding-system coding-system))
 
-(define-obsolete-function-alias
-  'rcirc-set-decode-coding-system
-  'set-rcirc-decode-coding-system
-  "28.1")
-
 (defun rcirc-set-encode-coding-system (coding-system)
   "Set the encode CODING-SYSTEM used in this channel."
   (interactive "zCoding system for outgoing messages: ")
   (setq-local rcirc-encode-coding-system coding-system))
 
-(define-obsolete-function-alias
-  'rcirc-set-encode-coding-system
-  'set-rcirc-encode-coding-system
-  "28.1")
-
 (defun rcirc-format (pre &optional replace)
   "Insert markup formatting PRE.
 PRE and \"^O\" (ASCII #x0f) will either be inserted around the