diff --git a/src/Util.php b/src/Util.php
index 220f98da..6bf1c802 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -317,7 +317,7 @@ public static function normalizeChars($string)
 
             'ß' => 'sz', 'þ' => 'thorn', 'º' => '', 'ª' => '', '°' => '',
         );
-        return strtr($string, $normalizeChars);
+        return preg_replace('/[^0-9a-zA-Z !*\-$\(\)\[\]\{\},.;:\/\\#%&@+=]/', '', strtr($string, $normalizeChars));
     }
 
     /**
@@ -474,6 +474,7 @@ public static function numberFormatGeral($n, $loop, $insert = 0)
     public static function formatCnab($tipo, $valor, $tamanho, $dec = 0, $sFill = '')
     {
         $tipo = self::upper($tipo);
+        $valor = self::upper(self::normalizeChars($valor));
         if (in_array($tipo, array('9', 9, 'N', '9L', 'NL'))) {
             if ($tipo == '9L' || $tipo == 'NL') {
                 $valor = self::onlyNumbers($valor);
@@ -486,7 +487,6 @@ public static function formatCnab($tipo, $valor, $tamanho, $dec = 0, $sFill = ''
         } elseif (in_array($tipo, array('A', 'X'))) {
             $left = '-';
             $type = 's';
-            $valor = self::upper(self::normalizeChars($valor));
         } else {
             throw new \Exception('Tipo inválido');
         }