diff --git a/install-dev/classes/controllerHttp.php b/install-dev/classes/controllerHttp.php
index b0dc56e4d..f53c30e0e 100644
--- a/install-dev/classes/controllerHttp.php
+++ b/install-dev/classes/controllerHttp.php
@@ -112,7 +112,8 @@ abstract class InstallControllerHttp
 			$session->last_step = self::$steps[0];
 
 		// Set timezone
-		@date_default_timezone_set($session->shop_timezone ? $session->shop_timezone : 'UTC');
+		if ($session->shop_timezone)
+			@date_default_timezone_set($session->shop_timezone);
 
 		// Get current step (check first if step is changed, then take it from session)
 		if (Tools::getValue('step'))
diff --git a/install-dev/init.php b/install-dev/init.php
index 4324a78d6..bc6770892 100644
--- a/install-dev/init.php
+++ b/install-dev/init.php
@@ -65,6 +65,8 @@ require_once(_PS_INSTALL_PATH_.'classes/xmlLoader.php');
 require_once(_PS_INSTALL_PATH_.'classes/simplexml.php');
 
 @set_time_limit(0);
+if (!@ini_get('date.timezone'))
+	@date_default_timezone_set('UTC');
 
 // Try to improve memory limit if it's under 32M
 if (Tools::getMemoryLimit() < Tools::getOctets('32M'))