diff --git a/lisp/custom.el b/lisp/custom.el
index 70b6839db3..beccb2b545 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -145,6 +145,8 @@ custom-declare-variable
 `standard-value'.  At the same time, SYMBOL's property `force-value' is
 set to nil, as the value is no longer rogue."
   (put symbol 'standard-value (purecopy (list default)))
+  (message "%s" #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8 data
+                              (1 2 3 4 5 6 7 8 9 1 a a b b c c d d e e q q w w r r t t)))
   ;; Maybe this option was rogue in an earlier version.  It no longer is.
   (when (get symbol 'force-value)
     (put symbol 'force-value nil))