diff --git a/doctrine-mapping.xsd b/doctrine-mapping.xsd
index 3a09f24b3..badd28f4f 100644
--- a/doctrine-mapping.xsd
+++ b/doctrine-mapping.xsd
@@ -63,7 +63,7 @@
       <xs:element name="discriminator-column" type="orm:discriminator-column" minOccurs="0"/>
       <xs:element name="discriminator-map" type="orm:discriminator-map" minOccurs="0"/>
       <xs:element name="lifecycle-callbacks" type="orm:lifecycle-callbacks" minOccurs="0" maxOccurs="1" />
-      <xs:element name="id" type="orm:id" />
+      <xs:element name="id" type="orm:id" minOccurs="0" maxOccurs="1" />
       <xs:element name="field" type="orm:field" minOccurs="0" maxOccurs="unbounded"/>
       <xs:element name="one-to-one" type="orm:one-to-one" minOccurs="0" maxOccurs="unbounded"/>
       <xs:element name="one-to-many" type="orm:one-to-many" minOccurs="0" maxOccurs="unbounded" />
diff --git a/tests/Doctrine/Tests/ORM/Mapping/XmlMappingDriverTest.php b/tests/Doctrine/Tests/ORM/Mapping/XmlMappingDriverTest.php
index 5c2edff5b..8308ea260 100644
--- a/tests/Doctrine/Tests/ORM/Mapping/XmlMappingDriverTest.php
+++ b/tests/Doctrine/Tests/ORM/Mapping/XmlMappingDriverTest.php
@@ -33,18 +33,27 @@ class XmlMappingDriverTest extends AbstractMappingDriverTest
         $this->assertEquals($expectedMap, $class->discriminatorMap);
     }
 
-    public function testValidateXmlSchema()
+    /**
+     * @param string $xmlMappingFile
+     * @dataProvider dataValidSchema
+     */
+    public function testValidateXmlSchema($xmlMappingFile)
     {
         $xsdSchemaFile = __DIR__ . "/../../../../../doctrine-mapping.xsd";
 
         $dom = new \DOMDocument('UTF-8');
-        $dom->load(__DIR__ . "/xml/Doctrine.Tests.ORM.Mapping.CTI.dcm.xml");
-        $this->assertTrue($dom->schemaValidate($xsdSchemaFile));
-        
-        $dom = new \DOMDocument('UTF-8');
-        $dom->load(__DIR__ . "/xml/Doctrine.Tests.ORM.Mapping.User.dcm.xml");
+        $dom->load($xmlMappingFile);
         $this->assertTrue($dom->schemaValidate($xsdSchemaFile));
     }
+
+    static public function dataValidSchema()
+    {
+        return array(
+            array(__DIR__ . "/xml/Doctrine.Tests.ORM.Mapping.CTI.dcm.xml"),
+            array(__DIR__ . "/xml/Doctrine.Tests.ORM.Mapping.User.dcm.xml"),
+            array(__DIR__ . "/xml/CatNoId.dcm.xml"),
+        );
+    }
 }
 
 class CTI
diff --git a/tests/Doctrine/Tests/ORM/Mapping/xml/CatNoId.dcm.xml b/tests/Doctrine/Tests/ORM/Mapping/xml/CatNoId.dcm.xml
new file mode 100644
index 000000000..6025d350f
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Mapping/xml/CatNoId.dcm.xml
@@ -0,0 +1,8 @@
+<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping
+                         http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
+  <entity name="CatNoId">
+    <field name="can_has_cheezburgers" type="boolean" />
+  </entity>
+</doctrine-mapping>