diff --git a/core/core-lib.el b/core/core-lib.el
index 254c778d7..3348ab550 100644
--- a/core/core-lib.el
+++ b/core/core-lib.el
@@ -199,10 +199,6 @@ If FETCHER is a function, ELT is used as the key in LIST (an alist)."
                   elt)
                ,list)))
 
-(defmacro delete! (elt list)
-  "Delete ELT from LIST in-place."
-  `(setq ,list (delete ,elt ,list)))
-
 (defmacro add-transient-hook! (hook-or-function &rest forms)
   "Attaches a self-removing function to HOOK-OR-FUNCTION.