diff --git a/src/Symfony/Component/Routing/Generator/UrlGenerator.php b/src/Symfony/Component/Routing/Generator/UrlGenerator.php
index 3e445a8245..3f959cdc98 100644
--- a/src/Symfony/Component/Routing/Generator/UrlGenerator.php
+++ b/src/Symfony/Component/Routing/Generator/UrlGenerator.php
@@ -110,7 +110,7 @@ class UrlGenerator implements UrlGeneratorInterface
                         throw new \InvalidArgumentException(sprintf('Parameter "%s" for route "%s" must match "%s" ("%s" given).', $token[3], $name, $token[2], $tparams[$token[3]]));
                     }
 
-                    if ($tparams[$token[3]] || !$optional) {
+                    if (!in_array($tparams[$token[3]], array(null, '', false), true) || !$optional) {
                         // %2F is not valid in a URL, so we don't encode it (which is fine as the requirements explicitly allowed it)
                         $url = $token[1].str_replace('%2F', '/', urlencode($tparams[$token[3]])).$url;
                     }
diff --git a/tests/Symfony/Tests/Component/Routing/Generator/UrlGeneratorTest.php b/tests/Symfony/Tests/Component/Routing/Generator/UrlGeneratorTest.php
index 6434459362..5d52d286f5 100644
--- a/tests/Symfony/Tests/Component/Routing/Generator/UrlGeneratorTest.php
+++ b/tests/Symfony/Tests/Component/Routing/Generator/UrlGeneratorTest.php
@@ -82,6 +82,14 @@ class UrlGeneratorTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('/app.php/testing//bar', $url);
     }
 
+    public function testRelativeUrlWithOptionalZeroParameter()
+    {
+        $routes = $this->getRoutes('test', new Route('/testing/{page}'));
+        $url = $this->getGenerator($routes)->generate('test', array('page' => 0), false);
+
+        $this->assertEquals('/app.php/testing/0', $url);
+    }
+
     public function testRelativeUrlWithExtraParameters()
     {
         $routes = $this->getRoutes('test', new Route('/testing'));