diff --git a/convert.php b/convert.php
index aa14da9..ccc24f3 100644
--- a/convert.php
+++ b/convert.php
@@ -53,6 +53,9 @@ class convert
     */
   public static function ucfirst ($str)
   {
+    if (! function_exists ("mb_strtoupper"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
     $a = mb_strtoupper (mb_substr ($str, 0, 1, 'UTF-8'), 'UTF-8');
     return $a . mb_substr ($str, 1, null, 'UTF-8');
   }
@@ -68,6 +71,9 @@ class convert
     */
   public static function ucwords ($str, $delimiters = " \t\r\n\f\v")
   {
+    if (! function_exists ("mb_strtolower"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
     $str = mb_strtolower ($str, "utf-8");
     $res = "";
     foreach  (preg_split ("#([".preg_quote ($delimiters)."]+)#", $str, -1,
diff --git a/dblayeroo.php b/dblayeroo.php
index 28ec5c7..0249338 100644
--- a/dblayeroo.php
+++ b/dblayeroo.php
@@ -72,6 +72,9 @@ class dblayeroo
                                $driver_options=null)
   /* {{{ */
   {
+    if (! function_exists ("mb_strlen"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
     $driver = @explode (":", $dsn);
     if (! isset ($driver[0]))
       $this->DBException (dgettext ("domframework", "No valid DSN provided"));
diff --git a/fts.php b/fts.php
index 17a040c..8f2ee43 100644
--- a/fts.php
+++ b/fts.php
@@ -51,6 +51,15 @@ class fts
     return $this->regexes;
   }
 
+  /** The constructor check the availability of the MB module
+    */
+  public function __construct ()
+  {
+    if (! function_exists ("mb_strlen"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
+  }
+
   /** Search the text provided in $query in the database
     * @param string $query The text to found in the database
     * @return array The operator and the associated regex value to search
diff --git a/getopts.php b/getopts.php
index b1e03e0..e673c7d 100644
--- a/getopts.php
+++ b/getopts.php
@@ -33,6 +33,15 @@ class getopts
     */
   private $programName;
 
+  /** The constructor check the availability of the MB module
+    */
+  public function __construct ()
+  {
+    if (! function_exists ("mb_strlen"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
+  }
+
   /** Set/Get the simulate value
     * @param string|null $simulate The simulate to get/set
     */