diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el
index da70ff00dd7..ae1a8b254ff 100644
--- a/lisp/vc/diff-mode.el
+++ b/lisp/vc/diff-mode.el
@@ -164,7 +164,7 @@ and hunk-based syntax highlighting otherwise as a fallback."
 ;;;;
 
 (defvar-keymap diff-mode-shared-map
-  :inherit special-mode-map
+  :parent special-mode-map
   "n" #'diff-hunk-next
   "N" #'diff-file-next
   "p" #'diff-hunk-prev