diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index bc5dfa17c1..6da6bc87ed 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -1275,7 +1275,18 @@ class Request
             return $locales[0];
         }
 
-        $preferredLanguages = array_values(array_intersect($preferredLanguages, $locales));
+        $extendedPreferredLanguages = array();
+        foreach ($preferredLanguages as $language) {
+            $extendedPreferredLanguages[] = $language;
+            if (false !== $position = strpos($language, '_')) {
+                $superLanguage = substr($language, 0, $position);
+                if (!in_array($superLanguage, $preferredLanguages)) {
+                    $extendedPreferredLanguages[] = $superLanguage;
+                }
+            }
+        }
+
+        $preferredLanguages = array_values(array_intersect($extendedPreferredLanguages, $locales));
 
         return isset($preferredLanguages[0]) ? $preferredLanguages[0] : $locales[0];
     }
@@ -1309,11 +1320,6 @@ class Request
                     for ($i = 0, $max = count($codes); $i < $max; $i++) {
                         if ($i == 0) {
                             $lang = strtolower($codes[0]);
-                            // First segment of compound language codes
-                            // is added to supported languages list
-                            if (!in_array($lang, $this->languages)) {
-                                $this->languages[] = $lang;
-                            }
                         } else {
                             $lang .= '_'.strtoupper($codes[$i]);
                         }
@@ -1321,9 +1327,7 @@ class Request
                 }
             }
 
-            if (!in_array($lang, $this->languages)) {
-                $this->languages[] = $lang;
-            }
+            $this->languages[] = $lang;
         }
 
         return $this->languages;
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index b4a43fc1f2..38ae748da6 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -881,6 +881,14 @@ class RequestTest extends \PHPUnit_Framework_TestCase
         $request = new Request();
         $request->headers->set('Accept-language', 'zh, en-us; q=0.8, en; q=0.6');
         $this->assertEquals('en', $request->getPreferredLanguage(array('fr', 'en')));
+
+        $request = new Request();
+        $request->headers->set('Accept-language', 'zh, en-us; q=0.8');
+        $this->assertEquals('en', $request->getPreferredLanguage(array('fr', 'en')));
+
+        $request = new Request();
+        $request->headers->set('Accept-language', 'zh, en-us; q=0.8, fr-fr; q=0.6, fr; q=0.5');
+        $this->assertEquals('en', $request->getPreferredLanguage(array('fr', 'en')));
     }
 
     public function testIsXmlHttpRequest()
@@ -951,8 +959,8 @@ class RequestTest extends \PHPUnit_Framework_TestCase
 
         $request = new Request();
         $request->headers->set('Accept-language', 'zh, en-us; q=0.8, en; q=0.6');
-        $this->assertEquals(array('zh', 'en', 'en_US'), $request->getLanguages());
-        $this->assertEquals(array('zh', 'en', 'en_US'), $request->getLanguages());
+        $this->assertEquals(array('zh', 'en_US', 'en'), $request->getLanguages());
+        $this->assertEquals(array('zh', 'en_US', 'en'), $request->getLanguages());
 
         $request = new Request();
         $request->headers->set('Accept-language', 'zh, en-us; q=0.6, en; q=0.8');
@@ -969,10 +977,6 @@ class RequestTest extends \PHPUnit_Framework_TestCase
         $request = new Request();
         $request->headers->set('Accept-language', 'zh, i-cherokee; q=0.6');
         $this->assertEquals(array('zh', 'cherokee'), $request->getLanguages());
-
-        $request = new Request();
-        $request->headers->set('Accept-language', 'en-us');
-        $this->assertEquals(array('en', 'en_US'), $request->getLanguages());
     }
 
     public function testGetRequestFormat()