diff --git a/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php b/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
index 72dd544fa..e0a53394c 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
@@ -431,7 +431,7 @@ class AnnotationDriver implements Driver
         $classes = array();
 
         if ($this->_paths) {
-            $declared = get_declared_classes();
+            $includedFiles = array();
 
             foreach ((array) $this->_paths as $path) {
                 if ( ! is_dir($path)) {
@@ -447,15 +447,19 @@ class AnnotationDriver implements Driver
                     if (($fileName = $file->getBasename($this->_fileExtension)) == $file->getBasename()) {
                         continue;
                     }
-
-                    require_once $file->getPathName();
+                    
+                    $sourceFile = realpath($file->getPathName());
+                    require_once $sourceFile;
+                    $includedFiles[] = $sourceFile;
                 }
             }
 
-            $declared = array_diff(get_declared_classes(), $declared);
+            $declared = get_declared_classes();
 
             foreach ($declared as $className) {
-                if ( ! $this->isTransient($className)) {
+                $rc = new \ReflectionClass($className);
+                $sourceFile = $rc->getFileName();
+                if (in_array($sourceFile, $includedFiles) && ! $this->isTransient($className)) {
                     $classes[] = $className;
                 }
             }
@@ -466,4 +470,4 @@ class AnnotationDriver implements Driver
         return $classes;
     }
 
-}
\ No newline at end of file
+}
diff --git a/tests/Doctrine/Tests/ORM/Mapping/AnnotationDriverTest.php b/tests/Doctrine/Tests/ORM/Mapping/AnnotationDriverTest.php
index 5c3341619..484ce01ba 100644
--- a/tests/Doctrine/Tests/ORM/Mapping/AnnotationDriverTest.php
+++ b/tests/Doctrine/Tests/ORM/Mapping/AnnotationDriverTest.php
@@ -36,6 +36,68 @@ class AnnotationDriverTest extends AbstractMappingDriverTest
         $this->assertEquals('string', $cm->fieldMappings['id']['type']);
     }
 
+    /**
+     * @group DDC-318
+     */
+    public function testGetAllClassNamesIsIdempotent()
+    {
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $original = $annotationDriver->getAllClassNames();
+
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $afterTestReset = $annotationDriver->getAllClassNames();
+
+        $this->assertEquals($original, $afterTestReset);
+    }
+
+    /**
+     * @group DDC-318
+     */
+    public function testGetAllClassNamesIsIdempotentEvenWithDifferentDriverInstances()
+    {
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $original = $annotationDriver->getAllClassNames();
+
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $afterTestReset = $annotationDriver->getAllClassNames();
+
+        $this->assertEquals($original, $afterTestReset);
+    }
+
+    /**
+     * @group DDC-318
+     */
+    public function testGetAllClassNamesReturnsAlreadyLoadedClassesIfAppropriate()
+    {
+        $rightClassName = 'Doctrine\Tests\Models\CMS\CmsUser';
+        $this->_ensureIsLoaded($rightClassName);
+
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $classes = $annotationDriver->getAllClassNames();
+
+        $this->assertContains($rightClassName, $classes);
+    }
+
+    /**
+     * @group DDC-318
+     */
+    public function testGetClassNamesReturnsOnlyTheAppropriateClasses()
+    {
+        $extraneousClassName = 'Doctrine\Tests\Models\ECommerce\ECommerceCart';
+        $this->_ensureIsLoaded($extraneousClassName);
+
+        $annotationDriver = $this->_loadDriverForCMSModels();
+        $classes = $annotationDriver->getAllClassNames();
+
+        $this->assertNotContains($extraneousClassName, $classes);
+    }
+
+    protected function _loadDriverForCMSModels()
+    {
+        $annotationDriver = $this->_loadDriver();
+        $annotationDriver->addPaths(array(__DIR__ . '/../../Models/CMS/'));
+        return $annotationDriver;
+    }
 
     protected function _loadDriver()
     {
@@ -44,6 +106,11 @@ class AnnotationDriverTest extends AbstractMappingDriverTest
         $reader->setDefaultAnnotationNamespace('Doctrine\ORM\Mapping\\');
         return new \Doctrine\ORM\Mapping\Driver\AnnotationDriver($reader);
     }
+
+    protected function _ensureIsLoaded($entityClassName)
+    {
+        new $entityClassName;
+    }
 }
 
 /**