diff --git a/shadowsocks/utils.py b/shadowsocks/utils.py
index 252c564..fee4afc 100644
--- a/shadowsocks/utils.py
+++ b/shadowsocks/utils.py
@@ -186,7 +186,7 @@ def get_config(is_local):
     if 'local_port' in config:
         config['local_port'] = int(config['local_port'])
 
-    if 'server_port' in config:
+    if 'server_port' in config and type(config['server_port']) != list:
         config['server_port'] = int(config['server_port'])
 
     logging.getLogger('').handlers = []