diff --git a/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php b/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
index 5a9b7e257e..4b568e5514 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
@@ -63,7 +63,7 @@ class MimeTypeTest extends TestCase
 
     public function testGuessWithDuplicatedFileType()
     {
-        $this->assertEquals('application/vnd.openxmlformats-officedocument.wordprocessingml.document', MimeTypeGuesser::getInstance()->guess(__DIR__.'/../Fixtures/test.docx'));
+        $this->assertSame('application/vnd.openxmlformats-officedocument.wordprocessingml.document', MimeTypeGuesser::getInstance()->guess(__DIR__.'/../Fixtures/test.docx'));
     }
 
     public function testGuessWithIncorrectPath()