diff --git a/composer.json b/composer.json
index f2bf364..a6b1deb 100644
--- a/composer.json
+++ b/composer.json
@@ -10,6 +10,7 @@
         }
     ],
     "require": {
+        "ext-bcmath" : "*",
         "php": ">=7.0.0"
     },
     "autoload": {
diff --git a/src/Iban.php b/src/Iban.php
index 8f4f4f2..e8ebeb0 100644
--- a/src/Iban.php
+++ b/src/Iban.php
@@ -25,10 +25,6 @@ class Iban
 
     /**
      * To Human Friendly.
-     *
-     * @param string $iban
-     *
-     * @return string
      */
     public static function toHumanFriendly(string $iban): string
     {
@@ -37,10 +33,6 @@ public static function toHumanFriendly(string $iban): string
 
     /**
      * Validate.
-     *
-     * @param string $iban
-     *
-     * @return bool
      */
     public static function validate(string $iban): bool
     {