diff --git a/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
index 7f8d341846f7d..a76baa9faa2f9 100644
--- a/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
+++ b/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
@@ -256,7 +256,7 @@ public function denormalize($data, $class, $format = null, array $context = arra
                 continue;
             }
 
-            $value = $this->validateAndDenormalize($class, $attribute, $value, $format, $context);
+            $value = $this->validateAndDenormalize(\get_class($object), $attribute, $value, $format, $context);
             try {
                 $this->setAttributeValue($object, $attribute, $value, $format, $context);
             } catch (InvalidArgumentException $e) {
diff --git a/src/Symfony/Component/Serializer/Normalizer/ObjectNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/ObjectNormalizer.php
index 6c9098528b67e..51efe2a559bd9 100644
--- a/src/Symfony/Component/Serializer/Normalizer/ObjectNormalizer.php
+++ b/src/Symfony/Component/Serializer/Normalizer/ObjectNormalizer.php
@@ -142,14 +142,24 @@ protected function getAllowedAttributes($classOrObject, array $context, $attribu
             return false;
         }
 
-        if (null !== $this->classDiscriminatorResolver && null !== $discriminatorMapping = $this->classDiscriminatorResolver->getMappingForMappedObject($classOrObject)) {
-            $allowedAttributes[] = $attributesAsString ? $discriminatorMapping->getTypeProperty() : new AttributeMetadata($discriminatorMapping->getTypeProperty());
+        $discriminatorMapping = $this->classDiscriminatorResolver ? $this->classDiscriminatorResolver->getMappingForMappedObject($classOrObject) : null;
 
-            foreach ($discriminatorMapping->getTypesMapping() as $class) {
-                $allowedAttributes = array_merge($allowedAttributes, parent::getAllowedAttributes($class, $context, $attributesAsString));
-            }
+        if (!$discriminatorMapping) {
+            return $allowedAttributes;
+        }
+
+        $allowedAttributes[] = $attributesAsString ? $discriminatorMapping->getTypeProperty() : new AttributeMetadata($discriminatorMapping->getTypeProperty());
+
+        $reflectionClass = new \ReflectionClass($classOrObject);
+
+        if (!$reflectionClass->isAbstract() && !$reflectionClass->isInterface()) {
+            return $allowedAttributes;
+        }
+
+        foreach ($discriminatorMapping->getTypesMapping() as $class) {
+            $allowedAttributes = \array_merge($allowedAttributes, parent::getAllowedAttributes($class, $context, $attributesAsString));
         }
 
-        return $allowedAttributes;
+        return \array_unique($allowedAttributes);
     }
 }