diff --git a/core/core-lib.el b/core/core-lib.el
index 36fddb72a..e237d3a59 100644
--- a/core/core-lib.el
+++ b/core/core-lib.el
@@ -692,72 +692,5 @@ the value of the variable `exec-path'."
           (funcall handler 'exec-path)
         exec-path))))
 
-;; DEPRECATED Remove once enough packages have adapted to these breaking changes.
-(eval-when! EMACS28+
-  (defmacro define-obsolete-variable-alias (obsolete-name current-name &optional when docstring)
-    "Make OBSOLETE-NAME a variable alias for CURRENT-NAME and mark it obsolete.
-
-WHEN should be a string indicating when the variable was first
-made obsolete, for example a date or a release number.
-
-This macro evaluates all its parameters, and both OBSOLETE-NAME
-and CURRENT-NAME should be symbols, so a typical usage would look like:
-
-  (define-obsolete-variable-alias 'foo-thing 'bar-thing \"27.1\")
-
-This macro uses `defvaralias' and `make-obsolete-variable' (which see).
-See the Info node `(elisp)Variable Aliases' for more details.
-
-If CURRENT-NAME is a defcustom or a defvar (more generally, any variable
-where OBSOLETE-NAME may be set, e.g. in an init file, before the
-alias is defined), then the define-obsolete-variable-alias
-statement should be evaluated before the defcustom, if user
-customizations are to be respected.  The simplest way to achieve
-this is to place the alias statement before the defcustom (this
-is not necessary for aliases that are autoloaded, or in files
-dumped with Emacs).  This is so that any user customizations are
-applied before the defcustom tries to initialize the
-variable (this is due to the way `defvaralias' works).
-
-For the benefit of Customize, if OBSOLETE-NAME has
-any of the following properties, they are copied to
-CURRENT-NAME, if it does not already have them:
-`saved-value', `saved-variable-comment'."
-    (declare (doc-string 4)
-             (advertised-calling-convention
-              (obsolete-name current-name when &optional docstring) "23.1"))
-    `(progn
-       (defvaralias ,obsolete-name ,current-name ,docstring)
-       (dolist (prop '(saved-value saved-variable-comment))
-         (and (get ,obsolete-name prop)
-              (null (get ,current-name prop))
-              (put ,current-name prop (get ,obsolete-name prop))))
-       (make-obsolete-variable ,obsolete-name ,current-name ,when)))
-
-  (defmacro define-obsolete-face-alias (obsolete-face current-face &optional when)
-    "Make OBSOLETE-FACE a face alias for CURRENT-FACE and mark it obsolete.
-WHEN should be a string indicating when the face was first made
-obsolete, for example a date or a release number."
-    `(progn (put ,obsolete-face 'face-alias ,current-face)
-            (put ,obsolete-face 'obsolete-face (or (purecopy ,when) t))))
-
-  (defmacro define-obsolete-function-alias (obsolete-name current-name &optional when docstring)
-    "Set OBSOLETE-NAME's function definition to CURRENT-NAME and mark it obsolete.
-
-\(define-obsolete-function-alias \\='old-fun \\='new-fun \"22.1\" \"old-fun's doc.\")
-
-is equivalent to the following two lines of code:
-
-\(defalias \\='old-fun \\='new-fun \"old-fun's doc.\")
-\(make-obsolete \\='old-fun \\='new-fun \"22.1\")
-
-WHEN should be a string indicating when the function was first
-made obsolete, for example a date or a release number.
-
-See the docstrings of `defalias' and `make-obsolete' for more details."
-    (declare (doc-string 4))
-    `(progn (defalias ,obsolete-name ,current-name ,docstring)
-            (make-obsolete ,obsolete-name ,current-name ,when))))
-
 (provide 'core-lib)
 ;;; core-lib.el ends here