diff --git a/erc-highlight-nicknames.el b/erc-highlight-nicknames.el
index 8ed47d4..4b9f170 100644
--- a/erc-highlight-nicknames.el
+++ b/erc-highlight-nicknames.el
@@ -88,8 +88,7 @@
 (require 'erc)
 (require 'erc-button)
 
-(defvar erc-highlight-facec 16)
-(defvar erc-highlight-faces
+(defconst erc-highlight-faces
   '(fg:erc-color-face0
     fg:erc-color-face1
     fg:erc-color-face2
@@ -109,13 +108,13 @@
 
 (defface erc-highlight-nick-base-face
   '((t nil))
-  "Base face used for highlighting nicks in erc. (Before the nick
-color is added)"
+  "Base face used for highlighting nicknames in ERC before the
+color is added."
   :group 'erc-faces)
 
 (defvar erc-highlight-face-table
   (make-hash-table :test 'equal)
-  "The hash table that contains unique erc nickname faces.")
+  "Hash table containing unique ERC nickname faces.")
 
 (defun hexcolor-luminance (color)
   "Returns the luminance of color COLOR. COLOR is a string \(e.g.
@@ -138,9 +137,7 @@ between 0 and 255."
             (- 65535 r) (- 65535 g) (- 65535 b))))
 
 (defun erc-highlight-nicknames ()
-  "Searches for nicknames and highlights them. Uses the first
-twelve digits of the MD5 message digest of the nickname as
-color (#rrrrggggbbbb)."
+  "Highlight nicknames using a random face from `erc-highlight-faces'."
   (with-syntax-table erc-button-syntax-table
     (let (bounds bound-start bound-end word color new-nick-face)
       (goto-char (point-min))
@@ -153,13 +150,15 @@ color (#rrrrggggbbbb)."
           (when (erc-get-server-user word)
             (setq new-nick-face (gethash word erc-highlight-face-table))
             (unless new-nick-face
-              (setq new-nick-face (nth (random erc-highlight-facec) erc-highlight-faces))
+              (setq new-nick-face
+                    (nth (random (length erc-highlight-faces))
+                         erc-highlight-faces))
               (setq color (face-foreground new-nick-face))
               (if (equal (cdr (assoc 'background-mode (frame-parameters))) 'dark)
                   ;; if too dark for background
                   (when (< (hexcolor-luminance color) 85)
                     (setq color (invert-color color)))
-                ;; if to bright for background
+                ;; if too bright for background
                 (when (> (hexcolor-luminance color) 170)
                   (setq color (invert-color color))))
               (copy-face 'erc-highlight-nick-base-face new-nick-face)
@@ -170,7 +169,7 @@ color (#rrrrggggbbbb)."
         ))))
 
 (define-erc-module highlight-nicknames nil
-  "Search through the buffer for nicknames, and highlight."
+  "Search through the buffer for nicknames, and highlight them."
   ((add-hook 'erc-insert-modify-hook 'erc-highlight-nicknames t))
   ((remove-hook 'erc-insert-modify-hook 'erc-highlight-nicknames)))