diff --git a/src/Enum.php b/src/Enum.php
index bfeaab4..ded6610 100755
--- a/src/Enum.php
+++ b/src/Enum.php
@@ -79,7 +79,7 @@ public function __toString()
      */
     public static function keys()
     {
-        return array_keys(static::toArray());
+        return array_keys(self::toArray());
     }
 
     /**
@@ -130,7 +130,7 @@ public static function isValidKey($key)
      */
     public static function search($value)
     {
-        return array_search($value, array_combine(self::keys(), self::toArray()));
+        return array_search($value, self::toArray());
     }
 
     /**