diff --git a/shadowsocks/manager.py b/shadowsocks/manager.py
index 199a96d..96dcb8b 100644
--- a/shadowsocks/manager.py
+++ b/shadowsocks/manager.py
@@ -149,4 +149,4 @@ class Manager(object):
 
 
 def run(config):
-    Manager(config).run()
\ No newline at end of file
+    Manager(config).run()
diff --git a/shadowsocks/server.py b/shadowsocks/server.py
index 8ff13d6..3489bf5 100755
--- a/shadowsocks/server.py
+++ b/shadowsocks/server.py
@@ -49,7 +49,7 @@ def main():
         else:
             config['port_password'][str(server_port)] = config['password']
 
-    if config['manager_port']:
+    if config.get('manager_port', 0):
         logging.info('entering manager mode')
         manager.run(config)
         return