diff --git a/nhentai/__init__.py b/nhentai/__init__.py
index 171ebc5..bcef93d 100644
--- a/nhentai/__init__.py
+++ b/nhentai/__init__.py
@@ -1,3 +1,3 @@
-__version__ = '0.4.11'
+__version__ = '0.4.12'
 __author__ = 'RicterZ'
 __email__ = 'ricterzheng@gmail.com'
diff --git a/nhentai/cmdline.py b/nhentai/cmdline.py
index ffc8a3e..69a38f3 100644
--- a/nhentai/cmdline.py
+++ b/nhentai/cmdline.py
@@ -120,7 +120,6 @@ def cmd_parser():
 
     try:
         sys.argv = [unicode(i.decode(sys.stdin.encoding)) for i in sys.argv]
-        print()
     except (NameError, TypeError):
         pass
     except UnicodeDecodeError:
@@ -157,7 +156,7 @@ def cmd_parser():
         exit(0)
         # TODO: search without language
 
-    if args.proxy:
+    if args.proxy is not None:
         proxy_url = urlparse(args.proxy)
         if not args.proxy == '' and proxy_url.scheme not in ('http', 'https'):
             logger.error('Invalid protocol \'{0}\' of proxy, ignored'.format(proxy_url.scheme))
@@ -171,7 +170,7 @@ def cmd_parser():
             write_config()
             exit(0)
 
-    if args.viewer_template:
+    if args.viewer_template is not None:
         if not args.viewer_template:
             args.viewer_template = 'default'
 
diff --git a/nhentai/command.py b/nhentai/command.py
index cbc50ed..8b05406 100644
--- a/nhentai/command.py
+++ b/nhentai/command.py
@@ -19,6 +19,11 @@ from nhentai.utils import generate_html, generate_cbz, generate_main_html, gener
 
 def main():
     banner()
+
+    if sys.version_info < (3, 0, 0):
+        logger.error('nhentai now only support Python 3.x')
+        exit(1)
+
     options = cmd_parser()
     logger.info('Using mirror: {0}'.format(BASE_URL))
 
@@ -114,8 +119,4 @@ signal.signal(signal.SIGINT, signal_handler)
 
 
 if __name__ == '__main__':
-    if sys.version_info < (3, 0, 0):
-        logger.error('nhentai now only support Python 3.x')
-        exit(1)
-
     main()
diff --git a/nhentai/logger.py b/nhentai/logger.py
index 8aa46b8..01b4929 100644
--- a/nhentai/logger.py
+++ b/nhentai/logger.py
@@ -1,7 +1,6 @@
 #
 # Copyright (C) 2010-2012 Vinay Sajip. All rights reserved. Licensed under the new BSD license.
 #
-from __future__ import print_function, unicode_literals
 import logging
 import re
 import platform