diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/CompilerDebugDumpPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/CompilerDebugDumpPass.php
index 62884df180..28ad7082fa 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/CompilerDebugDumpPass.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/CompilerDebugDumpPass.php
@@ -20,12 +20,12 @@ class CompilerDebugDumpPass implements CompilerPassInterface
 {
     public function process(ContainerBuilder $container)
     {
+        $filename = self::getCompilerLogFilename($container);
+
         $filesystem = new Filesystem();
-        $filesystem->dumpFile(
-            self::getCompilerLogFilename($container),
-            implode("\n", $container->getCompiler()->getLog()),
-            0666 & ~umask()
-        );
+        $filesystem->dumpFile($filename, implode("\n", $container->getCompiler()->getLog()), null);
+        // discard chmod failure (some filesystem may not support it)
+        @chmod($filename, 0666 & ~umask());
     }
 
     public static function getCompilerLogFilename(ContainerInterface $container)
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/ContainerBuilderDebugDumpPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/ContainerBuilderDebugDumpPass.php
index a9916cdbdc..6cf52b6522 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/ContainerBuilderDebugDumpPass.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/ContainerBuilderDebugDumpPass.php
@@ -28,11 +28,10 @@ class ContainerBuilderDebugDumpPass implements CompilerPassInterface
     public function process(ContainerBuilder $container)
     {
         $dumper = new XmlDumper($container);
+        $filename = $container->getParameter('debug.container.dump');
         $filesystem = new Filesystem();
-        $filesystem->dumpFile(
-            $container->getParameter('debug.container.dump'),
-            $dumper->dump(),
-            0666 & ~umask()
-        );
+        $filesystem->dumpFile($filename, $dumper->dump(), null);
+        // discard chmod failure (some filesystem may not support it)
+        @chmod($filename, 0666 & ~umask());
     }
 }
diff --git a/src/Symfony/Component/Config/ConfigCache.php b/src/Symfony/Component/Config/ConfigCache.php
index cbb1984272..73de9c2e5f 100644
--- a/src/Symfony/Component/Config/ConfigCache.php
+++ b/src/Symfony/Component/Config/ConfigCache.php
@@ -95,10 +95,12 @@ class ConfigCache
     {
         $mode = 0666 & ~umask();
         $filesystem = new Filesystem();
-        $filesystem->dumpFile($this->file, $content, $mode);
+        $filesystem->dumpFile($this->file, $content, null);
+        @chmod($this->file, $mode);
 
         if (null !== $metadata && true === $this->debug) {
-            $filesystem->dumpFile($this->getMetaFile(), serialize($metadata), $mode);
+            $filesystem->dumpFile($this->getMetaFile(), serialize($metadata), null);
+            @chmod($this->getMetaFile(), $mode);
         }
     }
 
diff --git a/src/Symfony/Component/Filesystem/CHANGELOG.md b/src/Symfony/Component/Filesystem/CHANGELOG.md
index e6aee66a57..5b5cd6a6c6 100644
--- a/src/Symfony/Component/Filesystem/CHANGELOG.md
+++ b/src/Symfony/Component/Filesystem/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.3.12
+------
+
+ * deprecated dumpFile() file mode argument.
+
 2.3.0
 -----
 
diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index 04f1d36131..69e3361146 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -444,10 +444,11 @@ class Filesystem
     /**
      * Atomically dumps content into a file.
      *
-     * @param  string  $filename The file to be written to.
-     * @param  string  $content  The data to write into the file.
-     * @param  integer $mode     The file mode (octal).
-     * @throws IOException       If the file cannot be written to.
+     * @param  string       $filename The file to be written to.
+     * @param  string       $content  The data to write into the file.
+     * @param  null|integer $mode     The file mode (octal). If null, file permissions are not modified
+     *                                Deprecated since version 2.3.12, to be removed in 3.0.
+     * @throws IOException            If the file cannot be written to.
      */
     public function dumpFile($filename, $content, $mode = 0666)
     {
@@ -466,6 +467,8 @@ class Filesystem
         }
 
         $this->rename($tmpFile, $filename, true);
-        $this->chmod($filename, $mode);
+        if (null !== $mode) {
+            $this->chmod($filename, $mode);
+        }
     }
 }
diff --git a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
index 5877e484c6..510db4556c 100644
--- a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
+++ b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
@@ -925,6 +925,21 @@ class FilesystemTest extends \PHPUnit_Framework_TestCase
         }
     }
 
+    public function testDumpFileWithNullMode()
+    {
+        $filename = $this->workspace.DIRECTORY_SEPARATOR.'foo'.DIRECTORY_SEPARATOR.'baz.txt';
+
+        $this->filesystem->dumpFile($filename, 'bar', null);
+
+        $this->assertFileExists($filename);
+        $this->assertSame('bar', file_get_contents($filename));
+
+        // skip mode check on Windows
+        if (!defined('PHP_WINDOWS_VERSION_MAJOR')) {
+            $this->assertEquals(600, $this->getFilePermissions($filename));
+        }
+    }
+
     public function testDumpFileOverwritesAnExistingFile()
     {
         $filename = $this->workspace.DIRECTORY_SEPARATOR.'foo.txt';