diff --git a/lisp/info.el b/lisp/info.el
index d2c0c669500..59416d79329 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -1415,6 +1415,8 @@ If no reference to follow, moves to the next node, or up if none."
   (define-key Info-mode-map "p" 'Info-prev)
   (define-key Info-mode-map "q" 'Info-exit)
   (define-key Info-mode-map "s" 'Info-search)
+  ;; For consistency with Rmail.
+  (define-key Info-mode-map "\M-s" 'Info-search)
   (define-key Info-mode-map "t" 'Info-top-node)
   (define-key Info-mode-map "u" 'Info-up)
   (define-key Info-mode-map "," 'Info-index-next)