diff --git a/aria2.py b/aria2.py
index 4d2c52c..629a946 100755
--- a/aria2.py
+++ b/aria2.py
@@ -13,19 +13,9 @@ else:
 from self_config import *
 
 
-DEFAULT_HOST = ARIA2_HOST
-DEFAULT_PORT = ARIA2_PORT
-DEFAULT_SECRET = ARIA2_SECRET
-DEFAULT_SCHEME = ARIA2_SCHEME
-
 class PyAria2(object):
 
-    def __init__(self,
-                 host=DEFAULT_HOST,
-                 port=DEFAULT_PORT,
-                 secret=DEFAULT_SECRET,
-                 scheme=DEFAULT_SCHEME,
-                 session=None):
+    def __init__(self,host,port,secret,scheme,session=None):
         '''
         PyAria2 constructor.
         host: string, aria2 rpc host, default is 'localhost'
@@ -63,7 +53,7 @@ class PyAria2(object):
             print('aria2 RPC server is started.')
         else:
             print('aria2 RPC server is already running.')
-        self.server_uri = DEFAULT_SCHEME+'://{}:{}/jsonrpc'.format(host, port)
+        self.server_uri = scheme+'://{}:{}/jsonrpc'.format(host, port)
         self.secret = secret
         self.server = xmlrpclib.ServerProxy(self.server_uri, allow_none=True)