diff --git a/.dir-locals.el b/.dir-locals.el
index b07a0dc50d8a4..fa031cbded990 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -17,7 +17,7 @@
 ((tcl-mode . ((tcl-indent-level . 4)
 	      (tcl-continued-indent-level . 4)
 	      (indent-tabs-mode . t)))
- (nil . ((bug-reference-url-format . "http://gcc.gnu.org/PR%s")))
+ (nil . ((bug-reference-url-format . "https://gcc.gnu.org/PR%s")))
  (c-mode . ((c-file-style . "GNU")
 	    (indent-tabs-mode . t)
 	    (fill-column . 79))))