diff --git a/lisp/repeat.el b/lisp/repeat.el
index 4dcd353e34..03e5b032fe 100644
--- a/lisp/repeat.el
+++ b/lisp/repeat.el
@@ -360,6 +360,12 @@ repeat-keep-prefix
   :group 'convenience
   :version "28.1")
 
+(defcustom repeat-foreign-key nil
+  "Whether to check if the last key exists in the repeat map."
+  :type 'boolean
+  :group 'convenience
+  :version "28.1")
+
 (defcustom repeat-echo-function #'repeat-echo-message
   "Function to display a hint about available keys.
 Function is called after every repeatable command with one argument:
@@ -428,7 +434,8 @@ repeat-post-hook
                        (eq current-minibuffer-command (cdr repeat--prev-mb)))
                    ;; Exit when the last char is not among repeatable keys,
                    ;; so e.g. `C-x u u' repeats undo, whereas `C-/ u' doesn't.
-                   (or (lookup-key map (this-command-keys-vector))
+                   (or repeat-foreign-key
+                       (lookup-key map (vector last-nonmenu-event))
                        prefix-arg))
 
               ;; Messaging