diff --git a/install/lib/installer_base.lib.php b/install/lib/installer_base.lib.php
index 088a98813c7fa8e495518fb5482cc2ab749cf6f3..d5f200661fa664346d75502ddd2a192e3a57b6e4 100644
--- a/install/lib/installer_base.lib.php
+++ b/install/lib/installer_base.lib.php
@@ -777,7 +777,7 @@ class installer_base {
 			$virtual_domains = "' '";
 
 		$content = str_replace('{hostname}', $conf['hostname'], $content);
-		if(!isset($old_options['DEFAULT_SERVER_LANGUAGE'])) $old_options['DEFAULT_SERVER_LANGUAGE'] = 'en';
+		if(!isset($old_options['DEFAULT_SERVER_LANGUAGE']) || $old_options['DEFAULT_SERVER_LANGUAGE'] == '') $old_options['DEFAULT_SERVER_LANGUAGE'] = 'en';
 		$content = str_replace('{default_language}', $old_options['DEFAULT_SERVER_LANGUAGE'], $content);
 		$content = str_replace('{virtual_domains}', $virtual_domains, $content);
 
diff --git a/install/tpl/mm_cfg.py.master b/install/tpl/mm_cfg.py.master
index 2e9a2227ae06b1c0028b36318c99b117e545c187..c0de780e0d19eec4ca07e900a7e1beb8459a3ba5 100644
--- a/install/tpl/mm_cfg.py.master
+++ b/install/tpl/mm_cfg.py.master
@@ -73,7 +73,7 @@ add_virtualhost(DEFAULT_URL_HOST, DEFAULT_EMAIL_HOST)
 
 #-------------------------------------------------------------
 # The default language for this server.
-DEFAULT_SERVER_LANGUAGE = '{default_language}'
+DEFAULT_SERVER_LANGUAGE = {default_language}
 
 #-------------------------------------------------------------
 # Iirc this was used in pre 2.1, leave it for now
diff --git a/server/conf/mm_cfg.py.master b/server/conf/mm_cfg.py.master
index 04ec0d5fdff3ce524ab51e27794da264af32ca4b..3dcf5a6a6156f50ce3feba2a3518d0ab40853a5d 100644
--- a/server/conf/mm_cfg.py.master
+++ b/server/conf/mm_cfg.py.master
@@ -73,7 +73,7 @@ add_virtualhost(DEFAULT_URL_HOST, DEFAULT_EMAIL_HOST)
 
 #-------------------------------------------------------------
 # The default language for this server.
-DEFAULT_SERVER_LANGUAGE = '{default_language}'
+DEFAULT_SERVER_LANGUAGE = {default_language}
 
 #-------------------------------------------------------------
 # Iirc this was used in pre 2.1, leave it for now