diff --git a/src/Symfony/Component/Validator/Constraints/NullValidator.php b/src/Symfony/Component/Validator/Constraints/NullValidator.php
index e8fa24ed74..9753f43315 100644
--- a/src/Symfony/Component/Validator/Constraints/NullValidator.php
+++ b/src/Symfony/Component/Validator/Constraints/NullValidator.php
@@ -27,6 +27,12 @@ class NullValidator extends ConstraintValidator
     public function validate($value, Constraint $constraint)
     {
         if (null !== $value) {
+            if (is_object($value)) {
+                $value = get_class($value);
+            } elseif (is_array($value)) {
+                $value = 'Array';
+            }
+
             $this->context->addViolation($constraint->message, array('{{ value }}' => $value));
         }
     }
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/NullValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/NullValidatorTest.php
index 4466aa17c9..d343c869fd 100644
--- a/src/Symfony/Component/Validator/Tests/Constraints/NullValidatorTest.php
+++ b/src/Symfony/Component/Validator/Tests/Constraints/NullValidatorTest.php
@@ -43,7 +43,7 @@ class NullValidatorTest extends \PHPUnit_Framework_TestCase
     /**
      * @dataProvider getInvalidValues
      */
-    public function testInvalidValues($value)
+    public function testInvalidValues($value, $readableValue)
     {
         $constraint = new Null(array(
             'message' => 'myMessage'
@@ -52,7 +52,7 @@ class NullValidatorTest extends \PHPUnit_Framework_TestCase
         $this->context->expects($this->once())
             ->method('addViolation')
             ->with('myMessage', array(
-                '{{ value }}' => $value,
+                '{{ value }}' => $readableValue,
             ));
 
         $this->validator->validate($value, $constraint);
@@ -61,10 +61,13 @@ class NullValidatorTest extends \PHPUnit_Framework_TestCase
     public function getInvalidValues()
     {
         return array(
-            array(0),
-            array(false),
-            array(true),
-            array(''),
+            array(0, 0),
+            array(false, false),
+            array(true, true),
+            array('', ''),
+            array('foo bar', 'foo bar'),
+            array(new \DateTime(), 'DateTime'),
+            array(array(), 'Array'),
         );
     }
 }