diff --git a/src/Faker/Provider/fr_FR/Company.php b/src/Faker/Provider/fr_FR/Company.php
index 81108873..0c9ca181 100644
--- a/src/Faker/Provider/fr_FR/Company.php
+++ b/src/Faker/Provider/fr_FR/Company.php
@@ -51,11 +51,6 @@ class Company extends \Faker\Provider\Company
      */
     protected static $companySuffix = array('SA', 'S.A.', 'SARL', 'S.A.R.L.', 'S.A.S.', 'et Fils');
 
-    /**
-     * @var string Siren format.
-     */
-    protected static $sirenFormat = "### ### ###";
-
     /**
      * Returns a random catch phrase noun.
      *
@@ -106,34 +101,95 @@ class Company extends \Faker\Provider\Company
     }
 
     /**
-     * Generates a siret number (14 digits).
-     * It is in fact the result of the concatenation of a siren number (9 digits),
-     * a sequential number (4 digits) and a control number (1 digit) concatenation.
-     * If $maxSequentialDigits is invalid, it is set to 2.
-     *
+     * Generates a siret number (14 digits) that passes the Luhn check. 
+     * Use $maxSequentialDigits to make sure the digits at position 2 to 5 are not zeros. 
+     * @see http://en.wikipedia.org/wiki/Luhn_algorithm
      * @param int $maxSequentialDigits The maximum number of digits for the sequential number (> 0 && <= 4).
-     *
      * @return string
      */
     public static function siret($maxSequentialDigits = 2)
     {
+        
         if ($maxSequentialDigits > 4 || $maxSequentialDigits <= 0) {
             $maxSequentialDigits = 2;
         }
-
-        $sequentialNumber = str_pad(static::randomNumber($maxSequentialDigits), 4, '0', STR_PAD_LEFT);
-
-        return  static::numerify(static::siren() . ' ' . $sequentialNumber . '#');
+        
+        $controlDigit = mt_rand(0, 9);
+        $siret = $sum = $controlDigit;
+        
+        $position = 2;
+        for ($i = 0; $i < $maxSequentialDigits; $i++) {
+            
+            $sequentialDigit = mt_rand(0, 9);
+            $isEven = $position++ % 2 === 0;
+            
+            $tmp = $isEven ? $sequentialDigit * 2 : $sequentialDigit;
+            if ($tmp >= 10) $tmp -= 9;
+            $sum += $tmp;
+            
+            $siret = $sequentialDigit . $siret;
+            
+        }
+        
+        $siret = str_pad($siret, 5, '0', STR_PAD_LEFT);
+        
+        $position = 6;
+        for ($i = 0; $i < 7; $i++) {
+            
+            $digit = mt_rand(0, 9);
+            $isEven = $position++ % 2 === 0;
+            
+            $tmp = $isEven ? $digit * 2 : $digit;
+            if ($tmp >= 10) $tmp -= 9;
+            $sum += $tmp;
+            
+            $siret = $digit . $siret;
+            
+        }
+        
+        $mod = $sum % 10;
+        if ($mod === 0) {
+            $siret = '00' . $siret;
+        } else {
+            // Use the odd position to avoid multiplying by two
+            $siret = '0' . (10 - $mod) . $siret;
+        }
+        
+        return preg_replace("/([0-9]{3})([0-9]{3})([0-9]{3})([0-9]{5})/", "$1 $2 $3 $4", $siret);
+        
     }
 
     /**
-     * Generates a siren number (9 digits).
-     *
+     * Generates a siren number (9 digits) that passes the Luhn check. 
+     * @see http://en.wikipedia.org/wiki/Luhn_algorithm
      * @return string
      */
     public static function siren()
     {
-        return static::numerify(static::$sirenFormat);
+        $siren = '';
+        $sum = 0;
+        for ($i = 9; $i > 1; $i--) {
+            
+            $digit = mt_rand(0, 9);
+            $isEven = $i % 2 === 0;
+            
+            $tmp = $isEven ? $digit * 2 : $digit;
+            if ($tmp >= 10) $tmp -= 9;
+            $sum += $tmp;
+            
+            $siren = $digit . $siren;
+            
+        }
+        
+        $mod = $sum % 10;
+        if ($mod === 0) {
+            $siren = '0' . $siren;
+        } else {
+            $siren = (10 - $mod) . $siren;
+        }
+        
+        return preg_replace("/([0-9]{3})([0-9]{3})([0-9]{3})/", "$1 $2 $3", $siren);
+        
     }
 
     /**
diff --git a/test/Faker/PHPUnit/Framework/Constraint/IsValidSiren.php b/test/Faker/PHPUnit/Framework/Constraint/IsValidSiren.php
new file mode 100644
index 00000000..b41930ac
--- /dev/null
+++ b/test/Faker/PHPUnit/Framework/Constraint/IsValidSiren.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Faker\PHPUnit\Framework\Constraint;
+
+class IsValidSiren extends IsValidSirenSiret
+{
+	
+	protected function getLength() {
+		return 9;
+	}
+    
+	protected function getName() {
+		return 'SIREN';
+	}
+    
+}
\ No newline at end of file
diff --git a/test/Faker/PHPUnit/Framework/Constraint/IsValidSirenSiret.php b/test/Faker/PHPUnit/Framework/Constraint/IsValidSirenSiret.php
new file mode 100644
index 00000000..c818e843
--- /dev/null
+++ b/test/Faker/PHPUnit/Framework/Constraint/IsValidSirenSiret.php
@@ -0,0 +1,36 @@
+<?php 
+
+namespace Faker\PHPUnit\Framework\Constraint;
+
+abstract class IsValidSirenSiret extends \PHPUnit_Framework_Constraint {
+	
+	protected function matches($other)
+    {
+    	
+    	$code = str_replace(' ', '', $other);
+    	
+    	if (strlen($code) != $this->getLength())
+    		return false;
+
+    	$sum = 0;
+    	// IMPORTANT : from right to left
+    	$position = 1;
+    	for ($i = strlen($code) - 1; $i >= 0; $i--) {
+    		$isEven = (($position++ % 2) === 0);
+    		$tmp = $isEven ? $code[$i] * 2 : $code[$i];
+    		if ($tmp >= 10) $tmp -= 9;
+			$sum += $tmp;
+    	}
+    	return ($sum % 10 === 0);
+    	
+    }
+    
+    public function toString() {
+    	return sprintf('is a valid %s number', $this->getName());
+    }
+    
+    abstract protected function getLength();
+    
+    abstract protected function getName();
+	
+}
\ No newline at end of file
diff --git a/test/Faker/PHPUnit/Framework/Constraint/IsValidSiret.php b/test/Faker/PHPUnit/Framework/Constraint/IsValidSiret.php
new file mode 100644
index 00000000..54da7b74
--- /dev/null
+++ b/test/Faker/PHPUnit/Framework/Constraint/IsValidSiret.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Faker\PHPUnit\Framework\Constraint;
+
+class IsValidSiret extends IsValidSirenSiret
+{
+	
+	protected function getLength() {
+		return 14;
+	}
+    
+	protected function getName() {
+		return 'SIRET';
+	}
+    
+}
\ No newline at end of file
diff --git a/test/Faker/Provider/fr_FR/CompanyTest.php b/test/Faker/Provider/fr_FR/CompanyTest.php
index fa482df3..190ea5ff 100644
--- a/test/Faker/Provider/fr_FR/CompanyTest.php
+++ b/test/Faker/Provider/fr_FR/CompanyTest.php
@@ -3,20 +3,37 @@
 namespace Faker\Test\Provider\fr_FR;
 
 use Faker\Provider\fr_FR\Company;
+use Faker\PHPUnit\Framework\Constraint as Constraint;
+
+require_once __DIR__ . '/../../PHPUnit/Framework/Constraint/IsValidSirenSiret.php';
+require_once __DIR__ . '/../../PHPUnit/Framework/Constraint/IsValidSiret.php';
+require_once __DIR__ . '/../../PHPUnit/Framework/Constraint/IsValidSiren.php';
 
 class CompanyTest extends \PHPUnit_Framework_TestCase
 {
+    private static function isValidSiret()
+    {
+        return new Constraint\IsValidSiret();
+    }
+    
+    private static function isValidSiren()
+    {
+        return new Constraint\IsValidSiren();
+    }
+    
     public function testParagraphWithNegativeNbDigitsReturnsAWellFormattedSiret()
     {
         $siret = Company::siret(-1);
-
+        
+        $this->assertThat($siret, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} 00[\d]{3}/", $siret);
     }
 
     public function testParagraphWithInvalidNbDigitsReturnsAWellFormattedSiret()
     {
         $siret = Company::siret(6);
-
+        
+        $this->assertThat($siret, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} 00[\d]{3}/", $siret);
     }
 
@@ -26,12 +43,24 @@ class CompanyTest extends \PHPUnit_Framework_TestCase
         $siret2 = Company::siret(2);
         $siret3 = Company::siret(3);
         $siret4 = Company::siret(4);
-
+        
+        $this->assertThat($siret1, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} 000[\d]{2}/", $siret1);
+        $this->assertThat($siret2, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} 00[\d]{3}/", $siret2);
+        $this->assertThat($siret3, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} 0[\d]{4}/", $siret3);
+        $this->assertThat($siret4, self :: isValidSiret());
         $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3} [\d]{5}/", $siret4);
     }
+    
+    public function testSirenReturnsAValidAndWellFormattedSiren()
+    {
+        $siret = Company::siren();
+        
+        $this->assertThat($siret, self :: isValidSiren());
+        $this->assertRegExp("/[\d]{3} [\d]{3} [\d]{3}/", $siret);
+    }
 
     public function testCatchPhraseValidationReturnsFalse()
     {