diff --git a/gvaweb/webtasks/tasks.py b/gvaweb/webtasks/tasks.py
index e102f57..d07f763 100644
--- a/gvaweb/webtasks/tasks.py
+++ b/gvaweb/webtasks/tasks.py
@@ -77,7 +77,7 @@ def create_web_vhost_config(username, sitename, wildcard):
     config_file = None
     try:
         nginx_temp_file, filename = mkstemp()
-        config_file = os.fdopen(nginx_temp_file, 'w')
+        config_file = os.fdopen(nginx_temp_file, 'wb')
         config_file.write(config_data.encode('utf8'))
     finally:
         if config_file: