diff --git a/config.php b/config.php
index 42cefed89ffa1eaceace08a8afd50ba3761f91d4..efe6d801a60e9b4def4816ef8229ccd9ea8517c1 100644
--- a/config.php
+++ b/config.php
@@ -14,21 +14,33 @@ $legalNotice =
 
 
 
+// Trouver une façon de définir $rootURL sans faire ça :
+
+if ($_SERVER['SERVER_NAME'] == 'localhost') {
+	
+	$rootURL = '/www/cesium-website';
+	
+} else {
+	
+	$rootURL = '';
+	
+}
+
 /* ====== i18n ====== */
 
 function checkAvailableLanguages ($langList) {
 	
-	foreach ($langList as $k => $v) {
+	foreach ($langList as $isoCode => $l) {
 		
-		$loc = setlocale(LC_ALL, $langList[$k]['folder'], ($langList[$k]['folder'] . '.utf8'));
+		$loc = setlocale(LC_ALL, $l['folder'], ($l['folder'] . '.utf8'));
 		
 		if ($loc === false) {
 			
-			$langList[$k] = NULL;
+			unset($langList[$isoCode]);
 				
 		} else {
 			
-			$langList[$k]['localeCode'] = $loc;
+			$langList[$isoCode]['localeCode'] = $loc;
 		}
 	}
 	
@@ -85,18 +97,6 @@ bindTextDomains($textDomains);
 
 
 
-// Trouver une façon de définir $rootURL sans faire ça :
-
-if ($_SERVER['SERVER_NAME'] == 'localhost') {
-	
-	$rootURL = '/www/cesium-website';
-	
-} else {
-	
-	$rootURL = '/';
-	
-}
-
 include('inc/functions.php');
 
 include('inc/display.php');
diff --git a/inc/functions.php b/inc/functions.php
index d468b7a30b95db22f6201c170adb47d232deb32c..4df84cc687f1b306a530ef7ac1bb383c6055edab 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -30,7 +30,8 @@ function getUserIpAddress ()
 		
 	} else if (array_key_exists('HTTP_X_FORWARDED_FOR', $_SERVER)) {
 
-		return array_pop(explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']));
+		$a = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
+		return array_pop($a);
 
 	} else {
 
diff --git a/inc/lang.php b/inc/lang.php
index 6102ef634882eb8a12ae7060c2e8d23376360852..cffea41edbfcd69da644f9ad3112198c6a2e8b56 100644
--- a/inc/lang.php
+++ b/inc/lang.php
@@ -24,10 +24,17 @@ function getLangFolder ($isoCode)
 function defineLang ()
 {
 	global $availableLanguages;
+	global $rootURL;
 	
 	if (isset($_GET['lang'])) {  /* From URL */
 
 		$lang = $_GET['lang'];
+		
+		
+		if (!in_array($lang, array_keys($availableLanguages))) {
+			
+			header('Location: '. $rootURL . '/'. DEFAULT_LANG . '/');
+		}
 
 	} else {  /* From browser (if visiting root page /) */