diff --git a/lisp/progmodes/bug-reference.el b/lisp/progmodes/bug-reference.el
index 210f0356084..13c52a4571b 100644
--- a/lisp/progmodes/bug-reference.el
+++ b/lisp/progmodes/bug-reference.el
@@ -73,10 +73,12 @@ so that it is considered safe, see `enable-local-variables'.")
   "Regular expression matching bug references.
 The second subexpression should match the bug reference (usually a number)."
   :type 'string
-  :safe 'stringp
   :version "24.3"			; previously defconst
   :group 'bug-reference)
 
+;;;###autoload
+(put 'bug-reference-bug-regexp 'safe-local-variable 'stringp)
+
 (defun bug-reference-set-overlay-properties ()
   "Set properties of bug reference overlays."
   (put 'bug-reference 'evaporate t)