diff --git a/el/sclang-dev.el b/el/sclang-dev.el
index 6deabea..b7e852a 100644
--- a/el/sclang-dev.el
+++ b/el/sclang-dev.el
@@ -1,3 +1,25 @@
+;; This program is free software; you can redistribute it and/or
+;; modify it under the terms of the GNU General Public License as
+;; published by the Free Software Foundation; either version 2 of the
+;; License, or (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program; if not, write to the Free Software
+;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
+;; USA
+
+
+(eval-when-compile
+  (require 'sclang-interp)
+  )
+
+
+
 (sclang-set-command-handler
   'openDevSource
   (lambda (file)
diff --git a/el/sclang-keys.el b/el/sclang-keys.el
index e159373..1acee63 100644
--- a/el/sclang-keys.el
+++ b/el/sclang-keys.el
@@ -25,7 +25,8 @@
 ;; (defun sclang-execute-key (char)
 ;;   (sclang-eval-string (sclang-format "Emacs.executeKey(%o)" char)))
 
-(require 'sclang-interp)
+(eval-and-compile (require 'sclang-util)
+                  (require 'sclang-interp))
 
 (defun sclang-read-keys ()
   (interactive)
@@ -34,7 +35,7 @@
     (while t
       (setq char (read-event))
       (clear-this-command-keys)
-      (when (char-valid-p char)
+      (when (characterp char)
 	(message "%s (%d)" (char-to-string char) char)
 	(sclang-eval-string (format "Emacs.keys.at(%d).value(%d)" char char))))))
 
diff --git a/el/sclang-minor-mode.el b/el/sclang-minor-mode.el
index 047ec38..23fd70b 100644
--- a/el/sclang-minor-mode.el
+++ b/el/sclang-minor-mode.el
@@ -16,6 +16,11 @@
 ;;; along with this program; if not, write to the Free Software
 ;;;  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 
+(eval-when-compile
+  (require 'sclang-mode)
+  )
+
+
 (easy-mmode-define-minor-mode sclang-minor-mode
   "Toggle sclang-minor-mode.
 With no argument, this command toggles the mode.
diff --git a/el/sclang-mode.el b/el/sclang-mode.el
index 0537e71..688a0f8 100644
--- a/el/sclang-mode.el
+++ b/el/sclang-mode.el
@@ -18,7 +18,8 @@
 (eval-when-compile
   (require 'cl)
   (load "cl-seq" nil t)
-  (require 'font-lock))
+  (require 'font-lock)
+  (require 'sclang-util))
 
 (require 'sclang-interp)
 (require 'sclang-language)
@@ -154,7 +155,7 @@
 ;; font-lock support
 ;; =====================================================================
 
-(defvar sclang-font-lock-keyword-list
+(defconst sclang-font-lock-keyword-list
   '(
     "arg"
     "classvar"
@@ -170,7 +171,7 @@
     )
   "*List of keywords to highlight in SCLang mode.")
 
-(defvar sclang-font-lock-builtin-list
+(defconst sclang-font-lock-builtin-list
   '(
     "false"
     "inf"
@@ -179,7 +180,7 @@
     )
   "*List of builtins to highlight in SCLang mode.")
 
-(defvar sclang-font-lock-method-list
+(defconst sclang-font-lock-method-list
   '(
     "ar"
     "for"
@@ -193,7 +194,7 @@
     )
   "*List of methods to highlight in SCLang mode.")
 
-(defvar sclang-font-lock-error-list
+(defconst sclang-font-lock-error-list
   '(
     "die"
     "error"
@@ -215,7 +216,7 @@
 (defvar sclang-font-lock-keywords-3 nil
   "Gaudy level highlighting for SCLang mode.")
 
-(defconst sclang-font-lock-keywords nil
+(defvar sclang-font-lock-keywords nil
   "Default expressions to highlight in SCLang mode.")
 
 (defconst sclang-font-lock-defaults '((sclang-font-lock-keywords
diff --git a/el/sclang-server.el b/el/sclang-server.el
index 533460b..9502875 100644
--- a/el/sclang-server.el
+++ b/el/sclang-server.el
@@ -15,8 +15,12 @@
 ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 ;; USA
 
-(eval-and-compile
-  (require 'cl))
+(eval-when-compile
+  (require 'cl)
+  (require 'sclang-util)
+  (require 'sclang-interp)
+  (require 'sclang-language)
+  (require 'sclang-mode))
 
 (defcustom sclang-server-panel "Server.default.makeWindow"
   "*Expression to execute when `sclang-show-server-panel' is invoked."
diff --git a/el/sclang-widgets.el b/el/sclang-widgets.el
index c127f0a..1e78605 100644
--- a/el/sclang-widgets.el
+++ b/el/sclang-widgets.el
@@ -26,6 +26,8 @@
 
 ;;; Code:
 
+(eval-when-compile (require 'sclang-util)
+                   (require 'sclang-language))
 (eval-and-compile (require 'sclang-interp))
 
 (defvar sclang-widgets nil)