diff --git a/src/Symfony/Component/Config/Resource/DirectoryResource.php b/src/Symfony/Component/Config/Resource/DirectoryResource.php
index 515fb5c42d..7ae5694ff0 100644
--- a/src/Symfony/Component/Config/Resource/DirectoryResource.php
+++ b/src/Symfony/Component/Config/Resource/DirectoryResource.php
@@ -38,7 +38,7 @@ class DirectoryResource implements ResourceInterface, \Serializable
      */
     public function __toString()
     {
-        return (string) $this->resource;
+        return md5(serialize(array($this->resource, $this->pattern)));
     }
 
     /**
diff --git a/src/Symfony/Component/Config/Tests/Resource/DirectoryResourceTest.php b/src/Symfony/Component/Config/Tests/Resource/DirectoryResourceTest.php
index 226e2807dc..2bbaadc3a7 100644
--- a/src/Symfony/Component/Config/Tests/Resource/DirectoryResourceTest.php
+++ b/src/Symfony/Component/Config/Tests/Resource/DirectoryResourceTest.php
@@ -54,7 +54,6 @@ class DirectoryResourceTest extends \PHPUnit_Framework_TestCase
     {
         $resource = new DirectoryResource($this->directory);
         $this->assertSame($this->directory, $resource->getResource(), '->getResource() returns the path to the resource');
-        $this->assertSame($this->directory, (string) $resource, '->__toString() returns the path to the resource');
     }
 
     public function testGetPattern()
@@ -87,6 +86,13 @@ class DirectoryResourceTest extends \PHPUnit_Framework_TestCase
         $this->assertFalse($resource->isFresh(time() + 10), '->isFresh() returns false if a new file is added');
     }
 
+    public function testIsFreshNewFileWithDifferentPattern()
+    {
+        $resource = new DirectoryResource($this->directory, '/.xml$/');
+        touch($this->directory.'/new.yaml', time() + 20);
+        $this->assertTrue($resource->isFresh(time() + 10), '->isFresh() returns true if a new file with a non-matching pattern is added');
+    }
+
     public function testIsFreshDeleteFile()
     {
         $resource = new DirectoryResource($this->directory);
@@ -149,4 +155,12 @@ class DirectoryResourceTest extends \PHPUnit_Framework_TestCase
         $this->assertSame($this->directory, $resource->getResource());
         $this->assertSame('/\.(foo|xml)$/', $resource->getPattern());
     }
+
+    public function testResourcesWithDifferentPatternsAreDifferent()
+    {
+        $resourceA = new DirectoryResource($this->directory, '/.xml$/');
+        $resourceB = new DirectoryResource($this->directory, '/.yaml$/');
+
+        $this->assertEquals(2, count(array_unique(array($resourceA, $resourceB))));
+    }
 }