diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index 4ee4f4156a1..6a808088cec 100644
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -505,7 +505,8 @@ This should be called very early, before the output buffer is cleared,
 because we want to record the \"previous\" position of point so we can
 restore it properly when going back."
   (with-current-buffer (help-buffer)
-    (kill-all-local-variables)
+    ;; Re-enable major mode, killing all unrelated local vars.
+    (funcall major-mode)
     (when help-xref-stack-item
       (push (cons (point) help-xref-stack-item) help-xref-stack)
       (setq help-xref-forward-stack nil))