diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php b/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
index 253ab6003..0c28ae473 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php
@@ -1937,19 +1937,22 @@ class ClassMetadataInfo implements ClassMetadata
     public function setDiscriminatorColumn($columnDef)
     {
         if ($columnDef !== null) {
+            if ( ! isset($columnDef['name'])) {
+                throw MappingException::nameIsMandatoryForDiscriminatorColumns($this->name);
+            }
+
             if (isset($this->fieldNames[$columnDef['name']])) {
                 throw MappingException::duplicateColumnName($this->name, $columnDef['name']);
             }
 
-            if ( ! isset($columnDef['name'])) {
-                throw MappingException::nameIsMandatoryForDiscriminatorColumns($this->name, $columnDef);
-            }
             if ( ! isset($columnDef['fieldName'])) {
                 $columnDef['fieldName'] = $columnDef['name'];
             }
+
             if ( ! isset($columnDef['type'])) {
                 $columnDef['type'] = "string";
             }
+
             if (in_array($columnDef['type'], array("boolean", "array", "object", "datetime", "time", "date"))) {
                 throw MappingException::invalidDiscriminatorColumnType($this->name, $columnDef['type']);
             }
diff --git a/lib/Doctrine/ORM/Mapping/MappingException.php b/lib/Doctrine/ORM/Mapping/MappingException.php
index c71c2e91c..0eff17cd6 100644
--- a/lib/Doctrine/ORM/Mapping/MappingException.php
+++ b/lib/Doctrine/ORM/Mapping/MappingException.php
@@ -226,6 +226,11 @@ class MappingException extends \Doctrine\ORM\ORMException
         return new self("Discriminator column type on entity class '$className' is not allowed to be '$type'. 'string' or 'integer' type variables are suggested!");
     }
 
+    public static function nameIsMandatoryForDiscriminatorColumns($className)
+    {
+        return new self("Discriminator column name on entity class '$className' is not defined.");
+    }
+
     public static function cannotVersionIdField($className, $fieldName)
     {
         return new self("Setting Id field '$fieldName' as versionale in entity class '$className' is not supported.");
diff --git a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataTest.php b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataTest.php
index c16eedba9..8f079e789 100644
--- a/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataTest.php
+++ b/tests/Doctrine/Tests/ORM/Mapping/ClassMetadataTest.php
@@ -596,6 +596,17 @@ class ClassMetadataTest extends \Doctrine\Tests\OrmTestCase
         $cm->validateAssocations();
     }
 
+    /**
+     * @expectedException \Doctrine\ORM\Mapping\MappingException
+     * @expectedExceptionMessage Discriminator column name on entity class 'Doctrine\Tests\Models\CMS\CmsUser' is not defined.
+     */
+    public function testNameIsMandatoryForDiscriminatorColumnsMappingException()
+    {
+        $cm = new ClassMetadata('Doctrine\Tests\Models\CMS\CmsUser');
+        $cm->initializeReflection(new \Doctrine\Common\Persistence\Mapping\RuntimeReflectionService);
+        $cm->setDiscriminatorColumn(array());
+    }
+
     /**
      * @group DDC-984
      * @group DDC-559