diff --git a/core/lib/Thelia/Core/HttpFoundation/Session/Session.php b/core/lib/Thelia/Core/HttpFoundation/Session/Session.php
index dd6af30d2..f2eaadc4d 100755
--- a/core/lib/Thelia/Core/HttpFoundation/Session/Session.php
+++ b/core/lib/Thelia/Core/HttpFoundation/Session/Session.php
@@ -47,7 +47,12 @@ class Session extends BaseSession
      */
     public function getLang($forceDefault = true)
     {
-        return $this->get("thelia.current.lang", $forceDefault ? Lang::getDefaultLanguage():null);
+        $lang = $this->get("thelia.current.lang");
+        if(null === $lang && $forceDefault)
+        {
+            $lang = Lang::getDefaultLanguage();
+        }
+        return $lang;
     }
 
     public function setLang(Lang $lang)
@@ -59,7 +64,12 @@ class Session extends BaseSession
 
     public function getAdminEditionLang()
     {
-        return $this->get('thelia.admin.edition.lang', Lang::getDefaultLanguage());
+        $lang = $this->get('thelia.admin.edition.lang');
+
+        if (null === $lang) {
+            $lang =  Lang::getDefaultLanguage();
+        }
+        return $lang;
     }
 
     public function setAdminEditionLang($langId)
@@ -76,7 +86,13 @@ class Session extends BaseSession
 
     public function getCurrency($forceDefault = true)
     {
-        return $this->get("thelia.current.currency", $forceDefault ? Currency::getDefaultCurrency():null);
+        $currency = $this->get("thelia.current.currency");
+
+        if(null === $currency && $forceDefault)
+        {
+            $currency = Currency::getDefaultCurrency();
+        }
+        return $currency;
     }
 
     // -- Customer user --------------------------------------------------------
diff --git a/core/lib/Thelia/Model/Tools/ModelCriteriaTools.php b/core/lib/Thelia/Model/Tools/ModelCriteriaTools.php
index 5e5dae010..c7426ef71 100755
--- a/core/lib/Thelia/Model/Tools/ModelCriteriaTools.php
+++ b/core/lib/Thelia/Model/Tools/ModelCriteriaTools.php
@@ -110,7 +110,7 @@ class ModelCriteriaTools
     {
         // If a lang has been requested, find the related Lang object, and get the locale
         if ($requestedLangId !== null) {
-            $localeSearch = LangQuery::create()->findOneById($requestedLangId);
+            $localeSearch = LangQuery::create()->findPk($requestedLangId);
 
             if ($localeSearch === null) {
                 throw new \InvalidArgumentException(sprintf('Incorrect lang argument given : lang ID %d not found', $requestedLangId));