--- a/lisp/simple.el	2014-11-21 09:21:50 +0000
+++ b/lisp/simple.el
@@ -1598,6 +1598,11 @@
                  (integer :tag "time" 2)
                  (other :tag "on")))
 
+(defcustom extended-command-suggest-shorter t
+  "Non-nil means show a shorter M-x invocation when there is one."
+  :group 'keyboard
+  :type 'boolean)
+
 (defun execute-extended-command--shorter-1 (name length)
   (cond
    ((zerop length) (list ""))
@@ -1680,7 +1685,8 @@ defun execute-extended-command (prefixarg &optional command-name typed)
                       ((numberp suggest-key-bindings) suggest-key-bindings)
                       (t 2)))))
       (when (and waited (not (consp unread-command-events)))
-        (unless (or binding executing-kbd-macro (not (symbolp function))
+        (unless (or (not extended-command-suggest-shorter)
+                    binding executing-kbd-macro (not (symbolp function))
                     (<= (length (symbol-name function)) 2))
           ;; There's no binding for CMD.  Let's try and find the shortest
           ;; string to use in M-x.