diff --git a/config.php b/config.php
index f15ae00..08befd5 100644
--- a/config.php
+++ b/config.php
@@ -20,6 +20,14 @@ class config
   /** Use the .php to protect the informations */
   public $confFile = "./datas/configuration.php";
 
+  /** The constructor can update the confFile variable if it is defined in a
+      constant */
+  public function __construct ()
+  {
+    if (defined("CONFIGFILE"))
+      $this->confFile = CONFIGFILE;
+  }
+
   /** List all the parameters configurable in the software */
   public function params ()
   {
@@ -40,9 +48,13 @@ class config
                               "<?php\r\n\$conf = array ();\r\n")
           === FALSE)
         throw new Exception (sprintf (
-                 "No configuration file '%s' available and it can't be created",
-                 $this->confFile));
+              _("No configuration file '%s' available and it can't be created"),
+              $this->confFile));
     }
+    elseif (! is_readable ($this->confFile))
+      throw new Exception (sprintf (
+                               _("The configuration file '%s' is not readable"),
+                                $this->confFile));
     $conf = array ();
     $rc = include ($this->confFile);
     if ($rc !== 1)
@@ -69,6 +81,10 @@ class config
                  "No configuration file '%s' available and it can't be created",
                  $this->confFile));
     }
+    elseif (! is_readable ($this->confFile))
+      throw new Exception (sprintf (
+                               _("The configuration file '%s' is not readable"),
+                                $this->confFile));
     if (!is_writeable ($this->confFile))
       throw new Exception (sprintf (
                                    "Configuration file '%s' is write protected",