diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
index d70f02ffa..089780775 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
@@ -70,6 +70,18 @@ class ClassMetadataFactory extends AbstractClassMetadataFactory
      */
     private $embeddablesActiveNesting = array();
 
+    /**
+     * {@inheritDoc}
+     */
+    protected function loadMetadata($name)
+    {
+        $loaded = parent::loadMetadata($name);
+
+        array_map([$this, 'resolveDiscriminatorValue'], array_map([$this, 'getMetadataFor'], $loaded));
+
+        return $loaded;
+    }
+
     /**
      * @param EntityManagerInterface $em
      */
@@ -270,9 +282,6 @@ class ClassMetadataFactory extends AbstractClassMetadataFactory
                 if ( ! $class->discriminatorColumn) {
                     throw MappingException::missingDiscriminatorColumn($class->name);
                 }
-            } else if ($parent && !$class->reflClass->isAbstract() && !in_array($class->name, array_values($class->discriminatorMap))) {
-                // enforce discriminator map for all entities of an inheritance hierarchy, otherwise problems will occur.
-                throw MappingException::mappedClassNotPartOfDiscriminatorMap($class->name, $class->rootEntityName);
             }
         } else if ($class->isMappedSuperclass && $class->name == $class->rootEntityName && (count($class->discriminatorMap) || $class->discriminatorColumn)) {
             // second condition is necessary for mapped superclasses in the middle of an inheritance hierarchy
@@ -288,6 +297,47 @@ class ClassMetadataFactory extends AbstractClassMetadataFactory
         return new ClassMetadata($className, $this->em->getConfiguration()->getNamingStrategy());
     }
 
+    /**
+     * Populates the discriminator value of the given metadata (if not set) by iterating over discriminator
+     * map classes and looking for a fitting one.
+     *
+     * @param ClassMetadata $metadata
+     *
+     * @return void
+     *
+     * @throws MappingException
+     */
+    private function resolveDiscriminatorValue(ClassMetadata $metadata)
+    {
+        if ($metadata->discriminatorValue
+            || ! $metadata->discriminatorMap
+            || $metadata->isMappedSuperclass
+            || $metadata->reflClass->isAbstract()
+        ) {
+            return;
+        }
+
+        // minor optimization: avoid loading related metadata when not needed
+        foreach ($metadata->discriminatorMap as $discriminatorValue => $discriminatorClass) {
+            if ($discriminatorClass === $metadata->name) {
+                $metadata->discriminatorValue = $discriminatorValue;
+
+                return;
+            }
+        }
+
+        // iterate over discriminator mappings and resolve actual referenced classes according to existing metadata
+        foreach ($metadata->discriminatorMap as $discriminatorValue => $discriminatorClass) {
+            if ($metadata->name === $this->getMetadataFor($discriminatorClass)->getName()) {
+                $metadata->discriminatorValue = $discriminatorValue;
+
+                return;
+            }
+        }
+
+        throw MappingException::mappedClassNotPartOfDiscriminatorMap($metadata->name, $metadata->rootEntityName);
+    }
+
     /**
      * Adds a default discriminator map if no one is given
      *
diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php b/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
index 67567456c..c3c8d8c83 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
@@ -2745,15 +2745,18 @@ class ClassMetadataInfo implements ClassMetadata
         $className = ltrim($className, '\\');
         $this->discriminatorMap[$name] = $className;
 
-        if ($this->name == $className) {
+        if ($this->name === $className) {
             $this->discriminatorValue = $name;
-        } else {
-            if ( ! class_exists($className)) {
-                throw MappingException::invalidClassInDiscriminatorMap($className, $this->name);
-            }
-            if (is_subclass_of($className, $this->name) && ! in_array($className, $this->subClasses)) {
-                $this->subClasses[] = $className;
-            }
+
+            return;
+        }
+
+        if ( ! (class_exists($className) || interface_exists($className))) {
+            throw MappingException::invalidClassInDiscriminatorMap($className, $this->name);
+        }
+
+        if (is_subclass_of($className, $this->name) && ! in_array($className, $this->subClasses)) {
+            $this->subClasses[] = $className;
         }
     }
 
diff --git a/tests/Doctrine/Tests/Models/CompositeKeyInheritance/JoinedRootClass.php b/tests/Doctrine/Tests/Models/CompositeKeyInheritance/JoinedRootClass.php
index f145ba259..3055b32e1 100644
--- a/tests/Doctrine/Tests/Models/CompositeKeyInheritance/JoinedRootClass.php
+++ b/tests/Doctrine/Tests/Models/CompositeKeyInheritance/JoinedRootClass.php
@@ -5,7 +5,7 @@ namespace Doctrine\Tests\Models\CompositeKeyInheritance;
  * @Entity
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"child" = "JoinedChildClass",})
+ * @DiscriminatorMap({"child" = "JoinedChildClass", "root" = "JoinedRootClass"})
  */
 class JoinedRootClass
 {
diff --git a/tests/Doctrine/Tests/Models/CompositeKeyInheritance/SingleRootClass.php b/tests/Doctrine/Tests/Models/CompositeKeyInheritance/SingleRootClass.php
index 1bbd09702..19b4b4b01 100644
--- a/tests/Doctrine/Tests/Models/CompositeKeyInheritance/SingleRootClass.php
+++ b/tests/Doctrine/Tests/Models/CompositeKeyInheritance/SingleRootClass.php
@@ -5,7 +5,7 @@ namespace Doctrine\Tests\Models\CompositeKeyInheritance;
  * @Entity
  * @InheritanceType("SINGLE_TABLE")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"child" = "SingleChildClass",})
+ * @DiscriminatorMap({"child" = "SingleChildClass", "root" = "SingleRootClass"})
  */
 class SingleRootClass
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1113Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1113Test.php
index 5bb007fd0..335c89dce 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1113Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1113Test.php
@@ -50,7 +50,7 @@ class DDC1113Test extends \Doctrine\Tests\OrmFunctionalTestCase
 /**
  * @Entity
  * @InheritanceType("SINGLE_TABLE")
- * @DiscriminatorMap({"car" = "DDC1113Car", "bus" = "DDC1113Bus"})
+ * @DiscriminatorMap({"vehicle" = "DDC1113Vehicle", "car" = "DDC1113Car", "bus" = "DDC1113Bus"})
  */
 class DDC1113Vehicle
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1454Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1454Test.php
index 162072965..f6b26253a 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1454Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1454Test.php
@@ -43,7 +43,7 @@ class DDC1454Picture extends DDC1454File
  * @Entity
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"picture" = "DDC1454Picture"})
+ * @DiscriminatorMap({"file" = "DDC1454File", "picture" = "DDC1454Picture"})
  */
 class DDC1454File
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1509Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1509Test.php
index 6ba0cd42f..2b7e9b377 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1509Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1509Test.php
@@ -115,7 +115,7 @@ class DDC1509Picture
  * @Entity
  * @InheritanceType("SINGLE_TABLE")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"file" = "DDC1509File"})
+ * @DiscriminatorMap({"abstractFile" = "DDC1509AbstractFile", "file" = "DDC1509File"})
  */
 class DDC1509AbstractFile
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1787Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1787Test.php
index 39fe48367..862d9196a 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1787Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1787Test.php
@@ -33,7 +33,7 @@ class DDC1787Test extends \Doctrine\Tests\OrmFunctionalTestCase
  * @Entity
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"bar" = "DDC1787Bar"})
+ * @DiscriminatorMap({"bar" = "DDC1787Bar", "foo" = "DDC1787Foo"})
  */
 class DDC1787Foo
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2012Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2012Test.php
index 549cf23cb..92510cb02 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2012Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2012Test.php
@@ -71,7 +71,8 @@ class DDC2012Test extends \Doctrine\Tests\OrmFunctionalTestCase
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="type_id", type="smallint")
  * @DiscriminatorMap({
- *      1 = "DDC2012ItemPerson"
+ *      1 = "DDC2012ItemPerson",
+ *      2 = "DDC2012Item"
  * })
  */
 class DDC2012Item
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2346Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2346Test.php
index 8bc803f29..8832b0f50 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2346Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2346Test.php
@@ -88,7 +88,7 @@ class DDC2346Foo
  * @Entity
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="discr", type="string")
- * @DiscriminatorMap({"baz" = "DDC2346Baz"})
+ * @DiscriminatorMap({"bar" = "DDC2346Bar", "baz" = "DDC2346Baz"})
  */
 class DDC2346Bar
 {
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3223Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3223Test.php
index 5677075dd..541221aa0 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3223Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3223Test.php
@@ -53,7 +53,8 @@ class Journalist extends Participant
  * @InheritanceType("JOINED")
  * @DiscriminatorColumn(name="discr", type="string")
  * @DiscriminatorMap({
- *     "journalist" = "Journalist",
+ *     "journalist"  = "Journalist",
+ *     "participant" = "Participant",
  * })
  */
 class Participant
@@ -71,6 +72,7 @@ class Participant
  * @DiscriminatorColumn(name="discr", type="string")
  * @DiscriminatorMap({
  *     "profile" = "ProfileStatus",
+ *     "status"  = "Status",
  * })
  */
 class Status
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3300Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3300Test.php
new file mode 100644
index 000000000..b7905ca3d
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC3300Test.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\ORM\Tools\ResolveTargetEntityListener;
+
+/**
+ * @group DDC-3300
+ */
+class DDC3300Test extends \Doctrine\Tests\OrmFunctionalTestCase
+{
+    public function testResolveTargetEntitiesChangesDiscriminatorMapValues()
+    {
+        $resolveTargetEntity = new ResolveTargetEntityListener();
+
+        $resolveTargetEntity->addResolveTargetEntity(
+            DDC3300BossInterface::INTERFACENAME,
+            DDC3300Boss::CLASSNAME,
+            array()
+        );
+
+        $resolveTargetEntity->addResolveTargetEntity(
+            DDC3300EmployeeInterface::INTERFACENAME,
+            DDC3300Employee::CLASSNAME,
+            array()
+        );
+
+        $this->_em->getEventManager()->addEventSubscriber($resolveTargetEntity);
+
+        $this->_schemaTool->createSchema(array(
+            $this->_em->getClassMetadata(DDC3300Person::CLASSNAME),
+        ));
+
+        $boss     = new DDC3300Boss();
+        $employee = new DDC3300Employee();
+
+        $this->_em->persist($boss);
+        $this->_em->persist($employee);
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $this->assertEquals($boss, $this->_em->find(DDC3300BossInterface::INTERFACENAME, $boss->id));
+        $this->assertEquals($employee, $this->_em->find(DDC3300EmployeeInterface::INTERFACENAME, $employee->id));
+    }
+}
+
+/**
+ * @Entity
+ * @InheritanceType("SINGLE_TABLE")
+ * @DdiscriminatorColumn(name="discr", type="string")
+ * @DiscriminatorMap({
+ *      "boss"     = "Doctrine\Tests\ORM\Functional\Ticket\DDC3300BossInterface",
+ *      "employee" = "Doctrine\Tests\ORM\Functional\Ticket\DDC3300EmployeeInterface"
+ * })
+ */
+abstract class DDC3300Person
+{
+    const CLASSNAME = __CLASS__;
+
+    /** @Id @Column(type="integer") @GeneratedValue(strategy="AUTO") */
+    public $id;
+}
+
+interface DDC3300BossInterface
+{
+    const INTERFACENAME = __CLASS__;
+}
+
+/** @Entity */
+class DDC3300Boss extends DDC3300Person implements DDC3300BossInterface
+{
+    const CLASSNAME = __CLASS__;
+}
+
+interface DDC3300EmployeeInterface
+{
+    const INTERFACENAME = __CLASS__;
+}
+
+/** @Entity */
+class DDC3300Employee extends DDC3300Person implements DDC3300EmployeeInterface
+{
+    const CLASSNAME = __CLASS__;
+}