diff --git a/.travis.yml b/.travis.yml
index a7c1f90..87c9a52 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,9 +4,13 @@ php:
   - 5.3
   - 5.4
   - 5.5
+  - 5.6
+  - hhvm
 
 before_script:
-  - wget http://getcomposer.org/composer.phar
-  - php composer.phar install
+  - composer self-update
+  - composer install --no-interaction --dev
 
-script: phpunit --configuration phpunit.xml tests
+script:
+  - vendor/bin/phpunit
+  - vendor/bin/phpcs --standard=PSR2 ./src/
diff --git a/README.md b/README.md
index fe0efdf..b9b9f6f 100755
--- a/README.md
+++ b/README.md
@@ -56,7 +56,12 @@ function setAction(Action $action) {
 - `__construct()` The constructor checks that the value exist in the enum
 - `__toString()` You can `echo $myValue`, it will display the enum value (value of the constant)
 - `getValue()` Returns the current value of the enum
-- `toArray()` (static) Returns an array of all possible values (constant name in key, constant value in value)
+- `getKey()` Returns the key of the current value on Enum
+- `keys()` (@static) Returns the names (keys) of all constants in the Enum class
+- `toArray()` (@static) method Returns all possible values as an array (constant name in key, constant value in value)
+- `isValid()` (@static) Check if tested value is valid on enum set
+- `isValidKey()` (@static) Check if tested key is valid on enum set
+- `search()` Return key for searched value
 
 ### Static methods
 
diff --git a/composer.json b/composer.json
index 9f4b589..0a925ba 100755
--- a/composer.json
+++ b/composer.json
@@ -5,9 +5,22 @@
     "keywords": ["enum"],
     "homepage": "http://github.com/myclabs/php-enum",
     "license": "MIT",
+    "authors": [
+        {
+            "name": "PHP Enum contributors",
+            "homepage": "https://github.com/myclabs/php-enum/graphs/contributors"
+        }
+    ],
     "autoload": {
-        "psr-0": {
+        "psr-4": {
             "MyCLabs\\Enum\\": "src/"
         }
+    },
+    "require": {
+        "php": ">=5.3"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "4.*",
+        "squizlabs/php_codesniffer": "1.*"
     }
 }
diff --git a/phpunit.xml b/phpunit.xml
index 387cab7..af5293b 100755
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -12,11 +12,9 @@
          stopOnFailure="false"
          syntaxCheck="false"
          bootstrap="./vendor/autoload.php">
-
     <testsuites>
-        <testsuite name="Enum Test Suite">
-            <directory>./tests</directory>
+        <testsuite name="PHP Enum Test Suite">
+            <directory suffix=".php">./tests</directory>
         </testsuite>
     </testsuites>
-
 </phpunit>
diff --git a/src/MyCLabs/Enum/Enum.php b/src/Enum.php
similarity index 55%
rename from src/MyCLabs/Enum/Enum.php
rename to src/Enum.php
index 5e6b148..939606c 100755
--- a/src/MyCLabs/Enum/Enum.php
+++ b/src/Enum.php
@@ -11,33 +11,38 @@
  *
  * Create an enum by implementing this class and adding class constants.
  *
+ * @package MyCLabs\Enum
  * @author Matthieu Napoli <matthieu@mnapoli.fr>
  */
 abstract class Enum
 {
     /**
      * Enum value
+     *
      * @var mixed
      */
     protected $value;
     
     /**
      * Store existing constants in a static cache per object.
+     *
      * @var array
      */
-    private static $constantsCache = array();
+    private static $cache = array();
 
     /**
      * Creates a new value of some type
+     *
      * @param mixed $value
+     *
      * @throws \UnexpectedValueException if incompatible type is given.
      */
     public function __construct($value)
     {
-        $possibleValues = self::toArray();
-        if (! in_array($value, $possibleValues)) {
+        if (!in_array($value, self::toArray())) {
             throw new \UnexpectedValueException("Value '$value' is not part of the enum " . get_called_class());
         }
+
         $this->value = $value;
     }
 
@@ -49,6 +54,16 @@ public function getValue()
         return $this->value;
     }
 
+    /**
+     * Returns the key of the current value on Enum
+     *
+     * @return mixed
+     */
+    public function getKey()
+    {
+        return self::search($this->value);
+    }
+
     /**
      * @return string
      */
@@ -57,24 +72,80 @@ public function __toString()
         return (string) $this->value;
     }
 
+    /**
+     * Returns the names (keys) of all constants in the Enum class
+     *
+     * @return array
+     */
+    public static function keys()
+    {
+        return array_keys(static::toArray());
+    }
+
     /**
      * Returns all possible values as an array
+     *
      * @return array Constant name in key, constant value in value
      */
     public static function toArray()
     {
-        $calledClass = get_called_class();
-        if(!array_key_exists($calledClass, self::$constantsCache)) {
-            $reflection = new \ReflectionClass($calledClass);
-            self::$constantsCache[$calledClass] = $reflection->getConstants();
+        $class = get_called_class();
+        if (!array_key_exists($class, self::$cache)) {
+            $reflection = new \ReflectionClass($class);
+            self::$cache[$class] = $reflection->getConstants();
         }
-        return self::$constantsCache[$calledClass];
+
+        return self::$cache[$class];
+    }
+
+    /**
+     * Check if is valid enum value
+     *
+     * @static
+     *
+     * @param $value
+     *
+     * @return bool
+     */
+    public static function isValid($value)
+    {
+        return in_array($value, self::toArray());
+    }
+
+    /**
+     * Check if is valid enum key
+     *
+     * @static
+     *
+     * @param $key
+     *
+     * @return bool
+     */
+    public static function isValidKey($key)
+    {
+        return in_array($key, self::keys());
+    }
+
+    /**
+     * Return key for value
+     *
+     * @static
+     *
+     * @param $value
+     *
+     * @return mixed
+     */
+    public static function search($value)
+    {
+        return array_search($value, array_combine(self::keys(), self::toArray()));
     }
 
     /**
      * Returns a value when called statically like so: MyEnum::SOME_VALUE() given SOME_VALUE is a class constant
+     *
      * @param string $name
      * @param array  $arguments
+     *
      * @return static
      * @throws \BadMethodCallException
      */
@@ -83,6 +154,7 @@ public static function __callStatic($name, $arguments)
         if (defined("static::$name")) {
             return new static(constant("static::$name"));
         }
+
         throw new \BadMethodCallException("No static method or enum constant '$name' in class " . get_called_class());
     }
 }
diff --git a/tests/EnumFixture.php b/tests/EnumFixture.php
new file mode 100644
index 0000000..24b60d1
--- /dev/null
+++ b/tests/EnumFixture.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * @link    http://github.com/myclabs/php-enum
+ * @license http://www.opensource.org/licenses/mit-license.php MIT (see the LICENSE file)
+ */
+
+namespace MyCLabs\Enum;
+
+/**
+ * Class EnumFixture
+ *
+ * @package MyCLabs\Enum
+ * @method static EnumFixture FOO()
+ * @method static EnumFixture BAR()
+ * @method static EnumFixture NUMBER()
+ * @author Daniel Costa <danielcosta@gmail.com
+ */
+class EnumFixture extends Enum
+{
+    const FOO = "foo";
+    const BAR = "bar";
+    const NUMBER = 42;
+}
diff --git a/tests/EnumTest.php b/tests/EnumTest.php
index 371d01d..1a13530 100755
--- a/tests/EnumTest.php
+++ b/tests/EnumTest.php
@@ -4,13 +4,12 @@
  * @license http://www.opensource.org/licenses/mit-license.php MIT (see the LICENSE file)
  */
 
-namespace UnitTest\MyCLabs\Enum\Enum;
-
-use MyCLabs\Enum\Enum;
+namespace MyCLabs\Enum;
 
 /**
  * Enum test
  *
+ * @package MyCLabs\Enum
  * @author Matthieu Napoli <matthieu@mnapoli.fr>
  */
 class EnumTest extends \PHPUnit_Framework_TestCase
@@ -30,10 +29,20 @@ public function testGetValue()
         $this->assertEquals(EnumFixture::NUMBER, $value->getValue());
     }
 
+    /**
+     * getKey()
+     */
+    public function testGetKey()
+    {
+        $value = new EnumFixture(EnumFixture::FOO);
+        $this->assertEquals('FOO', $value->getKey());
+        $this->assertNotEquals('BA', $value->getKey());
+    }
+
     /**
      * @expectedException \UnexpectedValueException
      */
-    public function testInvalidValue1()
+    public function testInvalidValueString()
     {
         new EnumFixture("test");
     }
@@ -41,7 +50,7 @@ public function testInvalidValue1()
     /**
      * @expectedException \UnexpectedValueException
      */
-    public function testInvalidValue2()
+    public function testInvalidValueInt()
     {
         new EnumFixture(1234);
     }
@@ -49,7 +58,7 @@ public function testInvalidValue2()
     /**
      * @expectedException \UnexpectedValueException
      */
-    public function testInvalidValue3()
+    public function testInvalidValueEmpty()
     {
         new EnumFixture(null);
     }
@@ -69,6 +78,21 @@ public function testToString()
         $this->assertEquals((string) EnumFixture::NUMBER, (string) $value);
     }
 
+    /**
+     * keys()
+     */
+    public function testKeys()
+    {
+        $values = EnumFixture::keys();
+        $this->assertInternalType("array", $values);
+        $expectedValues = array(
+            "FOO",
+            "BAR",
+            "NUMBER",
+        );
+        $this->assertEquals($expectedValues, $values);
+    }
+
     /**
      * toArray()
      */
@@ -96,24 +120,38 @@ public function testStaticAccess()
 
     /**
      * @expectedException \BadMethodCallException
-     * @expectedExceptionMessage No static method or enum constant 'UNKNOWN' in class UnitTest\MyCLabs\Enum\Enum\EnumFixture
+     * @expectedExceptionMessage No static method or enum constant 'UNKNOWN' in class
+     *                           UnitTest\MyCLabs\Enum\Enum\EnumFixture
      */
     public function testBadStaticAccess()
     {
         EnumFixture::UNKNOWN();
     }
-}
 
-/**
- * Fixture class
- *
- * @method static EnumFixture FOO()
- * @method static EnumFixture BAR()
- * @method static EnumFixture NUMBER()
- */
-class EnumFixture extends Enum
-{
-    const FOO = "foo";
-    const BAR = "bar";
-    const NUMBER = 42;
+    /**
+     * isValid()
+     */
+    public function testIsValid()
+    {
+        $this->assertTrue(EnumFixture::isValid('foo'));
+        $this->assertFalse(EnumFixture::isValid('baz'));
+    }
+
+    /**
+     * ssValidKey()
+     */
+    public function testIsValidKey()
+    {
+        $this->assertTrue(EnumFixture::isValidKey('FOO'));
+        $this->assertFalse(EnumFixture::isValidKey('BAZ'));
+    }
+
+    /**
+     * search()
+     */
+    public function testSearch()
+    {
+        $this->assertEquals('FOO', EnumFixture::search('foo'));
+        $this->assertNotEquals('FOO', EnumFixture::isValidKey('baz'));
+    }
 }