diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 0fa2da23721..6790f199206 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -264,11 +264,12 @@ facilities that have been added more recently."
 ;; this way can never be run in Emacs 18, and may even cause it to crash.")
 
 (defcustom byte-optimize t
-  "*Enables optimization in the byte compiler.
-nil means don't do any optimization.
-t means do all optimizations.
-`source' means do source-level optimizations only.
-`byte' means do code-level optimizations only."
+  "*Enable optimization in the byte compiler.
+Possible values are:
+  nil      - no optimization
+  t        - all optimizations
+  `source' - source-level optimizations only
+  `byte'   - code-level optimizations only"
   :group 'bytecomp
   :type '(choice (const :tag "none" nil)
 		 (const :tag "all" t)
@@ -336,7 +337,7 @@ If it is 'byte, then only byte-level optimizations will be logged."
 (defcustom byte-compile-warnings t
   "*List of warnings that the byte-compiler should issue (t for all).
 
-Elements of the list may be be:
+Elements of the list may be:
 
   free-vars   references to variables not in the current lexical scope.
   unresolved  calls to unknown functions.