diff --git a/lisp/files.el b/lisp/files.el
index 0968d0fef48..102f0d3ba4f 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -153,7 +153,7 @@ The value is a list of regular expressions.
 If the file name matches one of these regular expressions,
 then `revert-buffer' reverts the file without querying
 if the file has changed on disk and you have not edited the buffer."
-  :type 'boolean
+  :type '(repeat regexp)
   :group 'find-file)
 
 (defvar buffer-file-number nil