diff --git a/common/framework/URL.php b/common/framework/URL.php
index e4dadae3f..6752eb99d 100644
--- a/common/framework/URL.php
+++ b/common/framework/URL.php
@@ -258,7 +258,12 @@ class URL
 			$position = 0;
 		}
 
-		if (function_exists('idn_to_utf8'))
+		$domain = (string)$domain;
+		if ($domain === '')
+		{
+			$new_domain = '';
+		}
+		elseif (function_exists('idn_to_utf8'))
 		{
 			$new_domain = idn_to_utf8($domain);
 		}
diff --git a/modules/module/module.model.php b/modules/module/module.model.php
index 79c1c2f7d..4530f252b 100644
--- a/modules/module/module.model.php
+++ b/modules/module/module.model.php
@@ -195,13 +195,13 @@ class ModuleModel extends Module
 	/**
 	 * @brief Get the default mid according to the domain
 	 */
-	public static function getDefaultMid($domain = null)
+	public static function getDefaultMid($domain = '')
 	{
 		// Get current domain.
 		$domain = $domain ? Rhymix\Framework\URL::decodeIdna($domain) : Rhymix\Framework\URL::getCurrentDomain();
 
 		// Find the domain information.
-		$domain_info = self::getSiteInfoByDomain($domain);
+		$domain_info = $domain ? self::getSiteInfoByDomain($domain) : null;
 		if (!$domain_info)
 		{
 			$domain_info = self::getDefaultDomainInfo();