diff --git a/src/Symfony/Component/Locale/Stub/StubLocale.php b/src/Symfony/Component/Locale/Stub/StubLocale.php
index 7465aa28b5..1352f317b3 100644
--- a/src/Symfony/Component/Locale/Stub/StubLocale.php
+++ b/src/Symfony/Component/Locale/Stub/StubLocale.php
@@ -466,7 +466,9 @@ class StubLocale
      */
     public static function setDefault($locale)
     {
-        throw new MethodNotImplementedException(__METHOD__);
+        if ('en' !== $locale) {
+            throw new MethodNotImplementedException(__METHOD__);
+        }
     }
 
     public static function getDataDirectory()
diff --git a/src/Symfony/Component/Locale/Tests/Stub/StubLocaleTest.php b/src/Symfony/Component/Locale/Tests/Stub/StubLocaleTest.php
index d9e79dc517..e9c1e0f94a 100644
--- a/src/Symfony/Component/Locale/Tests/Stub/StubLocaleTest.php
+++ b/src/Symfony/Component/Locale/Tests/Stub/StubLocaleTest.php
@@ -252,4 +252,9 @@ class StubLocaleTest extends LocaleTestCase
     {
         StubLocale::setDefault('pt_BR');
     }
+
+    public function testSetDefaultAcceptsEn()
+    {
+        StubLocale::setDefault('en');
+    }
 }