diff --git a/lib/Doctrine/ORM/EntityNotFoundException.php b/lib/Doctrine/ORM/EntityNotFoundException.php
index 18278f715..afe2f2242 100644
--- a/lib/Doctrine/ORM/EntityNotFoundException.php
+++ b/lib/Doctrine/ORM/EntityNotFoundException.php
@@ -28,10 +28,24 @@ namespace Doctrine\ORM;
 class EntityNotFoundException extends ORMException
 {
     /**
-     * Constructor.
+     * Static constructor.
+     *
+     * @param string   $className
+     * @param string[] $id
+     *
+     * @return self
      */
-    public function __construct($class)
+    public static function fromClassNameAndIdentifier($className, array $id)
     {
-        parent::__construct("Entity of type '{$class}' was not found.");
+        $ids = array();
+
+        foreach ($id as $key => $value) {
+            $ids[] = $key . '(' . $value . ')';
+        }
+
+
+        return new self(
+            'Entity of type \'' . $className . '\'' . ($ids ? ' for IDs ' . implode(', ', $ids) : '') . ' was not found'
+        );
     }
 }
diff --git a/lib/Doctrine/ORM/Proxy/ProxyFactory.php b/lib/Doctrine/ORM/Proxy/ProxyFactory.php
index 8d4cb5662..157ae643f 100644
--- a/lib/Doctrine/ORM/Proxy/ProxyFactory.php
+++ b/lib/Doctrine/ORM/Proxy/ProxyFactory.php
@@ -28,6 +28,7 @@ use Doctrine\Common\Proxy\ProxyGenerator;
 use Doctrine\ORM\Persisters\EntityPersister;
 use Doctrine\ORM\EntityManager;
 use Doctrine\ORM\EntityNotFoundException;
+use Doctrine\ORM\Utility\IdentifierFlattener;
 
 /**
  * This factory is used to create proxy objects for entities at runtime.
@@ -54,6 +55,13 @@ class ProxyFactory extends AbstractProxyFactory
      */
     private $proxyNs;
 
+    /**
+     * The IdentifierFlattener used for manipulating identifiers
+     *
+     * @var \Doctrine\ORM\Utility\IdentifierFlattener
+     */
+    private $identifierFlattener;
+
     /**
      * Initializes a new instance of the <tt>ProxyFactory</tt> class that is
      * connected to the given <tt>EntityManager</tt>.
@@ -71,10 +79,10 @@ class ProxyFactory extends AbstractProxyFactory
         $proxyGenerator->setPlaceholder('baseProxyInterface', 'Doctrine\ORM\Proxy\Proxy');
         parent::__construct($proxyGenerator, $em->getMetadataFactory(), $autoGenerate);
 
-        $this->em      = $em;
-        $this->uow     = $em->getUnitOfWork();
-        $this->proxyNs = $proxyNs;
-
+        $this->em                  = $em;
+        $this->uow                 = $em->getUnitOfWork();
+        $this->proxyNs             = $proxyNs;
+        $this->identifierFlattener = new IdentifierFlattener($this->uow, $em->getMetadataFactory());
     }
 
     /**
@@ -115,8 +123,9 @@ class ProxyFactory extends AbstractProxyFactory
      */
     private function createInitializer(ClassMetadata $classMetadata, EntityPersister $entityPersister)
     {
+        $identifierFlattener = $this->identifierFlattener;
         if ($classMetadata->getReflectionClass()->hasMethod('__wakeup')) {
-            return function (BaseProxy $proxy) use ($entityPersister, $classMetadata) {
+            return function (BaseProxy $proxy) use ($entityPersister, $classMetadata, $identifierFlattener) {
                 $initializer = $proxy->__getInitializer();
                 $cloner      = $proxy->__getCloner();
 
@@ -138,17 +147,22 @@ class ProxyFactory extends AbstractProxyFactory
                 $proxy->__setInitialized(true);
                 $proxy->__wakeup();
 
-                if (null === $entityPersister->loadById($classMetadata->getIdentifierValues($proxy), $proxy)) {
+                $identifier = $classMetadata->getIdentifierValues($proxy);
+
+                if (null === $entityPersister->loadById($identifier, $proxy)) {
                     $proxy->__setInitializer($initializer);
                     $proxy->__setCloner($cloner);
                     $proxy->__setInitialized(false);
 
-                    throw new EntityNotFoundException($classMetadata->getName());
+                    throw EntityNotFoundException::fromClassNameAndIdentifier(
+                        $classMetadata->getName(),
+                        $identifierFlattener->flattenIdentifier($classMetadata, $identifier)
+                    );
                 }
             };
         }
 
-        return function (BaseProxy $proxy) use ($entityPersister, $classMetadata) {
+        return function (BaseProxy $proxy) use ($entityPersister, $classMetadata, $identifierFlattener) {
             $initializer = $proxy->__getInitializer();
             $cloner      = $proxy->__getCloner();
 
@@ -169,12 +183,17 @@ class ProxyFactory extends AbstractProxyFactory
 
             $proxy->__setInitialized(true);
 
-            if (null === $entityPersister->loadById($classMetadata->getIdentifierValues($proxy), $proxy)) {
+            $identifier = $classMetadata->getIdentifierValues($proxy);
+
+            if (null === $entityPersister->loadById($identifier, $proxy)) {
                 $proxy->__setInitializer($initializer);
                 $proxy->__setCloner($cloner);
                 $proxy->__setInitialized(false);
 
-                throw new EntityNotFoundException($classMetadata->getName());
+                throw EntityNotFoundException::fromClassNameAndIdentifier(
+                    $classMetadata->getName(),
+                    $identifierFlattener->flattenIdentifier($classMetadata, $identifier)
+                );
             }
         };
     }
@@ -191,19 +210,25 @@ class ProxyFactory extends AbstractProxyFactory
      */
     private function createCloner(ClassMetadata $classMetadata, EntityPersister $entityPersister)
     {
-        return function (BaseProxy $proxy) use ($entityPersister, $classMetadata) {
+        $identifierFlattener = $this->identifierFlattener;
+
+        return function (BaseProxy $proxy) use ($entityPersister, $classMetadata, $identifierFlattener) {
             if ($proxy->__isInitialized()) {
                 return;
             }
 
             $proxy->__setInitialized(true);
             $proxy->__setInitializer(null);
- 
-            $class    = $entityPersister->getClassMetadata();
-            $original = $entityPersister->loadById($classMetadata->getIdentifierValues($proxy));
+
+            $class      = $entityPersister->getClassMetadata();
+            $identifier = $classMetadata->getIdentifierValues($proxy);
+            $original   = $entityPersister->loadById($identifier);
 
             if (null === $original) {
-                throw new EntityNotFoundException($classMetadata->getName());
+                throw EntityNotFoundException::fromClassNameAndIdentifier(
+                    $classMetadata->getName(),
+                    $identifierFlattener->flattenIdentifier($classMetadata, $identifier)
+                );
             }
 
             foreach ($class->getReflectionClass()->getProperties() as $property) {
diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 8789b5f81..e91ff3d12 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -1843,7 +1843,10 @@ class UnitOfWork implements PropertyChangedListener
                     // If the identifier is ASSIGNED, it is NEW, otherwise an error
                     // since the managed entity was not found.
                     if ( ! $class->isIdentifierNatural()) {
-                        throw new EntityNotFoundException($class->getName());
+                        throw EntityNotFoundException::fromClassNameAndIdentifier(
+                            $class->getName(),
+                            $this->identifierFlattener->flattenIdentifier($class, $id)
+                        );
                     }
 
                     $managedCopy = $this->newInstance($class);
diff --git a/tests/Doctrine/Tests/ORM/EntityNotFoundExceptionTest.php b/tests/Doctrine/Tests/ORM/EntityNotFoundExceptionTest.php
new file mode 100644
index 000000000..7dce1b171
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/EntityNotFoundExceptionTest.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Doctrine\Tests\ORM;
+
+use Doctrine\ORM\EntityNotFoundException;
+use PHPUnit_Framework_TestCase;
+
+/**
+ * Tests for {@see \Doctrine\ORM\EntityNotFoundException}
+ *
+ * @covers \Doctrine\ORM\EntityNotFoundException
+ */
+class EntityNotFoundExceptionTest extends PHPUnit_Framework_TestCase
+{
+    public function testFromClassNameAndIdentifier()
+    {
+        $exception = EntityNotFoundException::fromClassNameAndIdentifier(
+            'foo',
+            array('foo' => 'bar')
+        );
+
+        $this->assertInstanceOf('Doctrine\ORM\EntityNotFoundException', $exception);
+        $this->assertSame('Entity of type \'foo\' for IDs foo(bar) was not found', $exception->getMessage());
+
+        $exception = EntityNotFoundException::fromClassNameAndIdentifier(
+            'foo',
+            array()
+        );
+
+        $this->assertInstanceOf('Doctrine\ORM\EntityNotFoundException', $exception);
+        $this->assertSame('Entity of type \'foo\' was not found', $exception->getMessage());
+    }
+}