diff --git a/powerline/renderer.py b/powerline/renderer.py
index f2c2bd8d..70ce4f1c 100644
--- a/powerline/renderer.py
+++ b/powerline/renderer.py
@@ -29,7 +29,7 @@ class Renderer(object):
 		else:
 			return self.theme
 
-	def render(self, mode, width=None, theme=None, segments=None, side=None):
+	def render(self, mode=None, width=None, theme=None, segments=None, side=None):
 		'''Render all segments.
 
 		When a width is provided, low-priority segments are dropped one at
diff --git a/scripts/powerline-prompt b/scripts/powerline-prompt
index 1670d882..24ccb1da 100755
--- a/scripts/powerline-prompt
+++ b/scripts/powerline-prompt
@@ -19,7 +19,7 @@ parser.add_argument('--ext', default='shell')
 if __name__ == '__main__':
 	args = parser.parse_args()
 	powerline = Powerline(ext=args.ext, renderer_module=args.renderer_module)
-	rendered = powerline.renderer.render(None, side=args.side)
+	rendered = powerline.renderer.render(side=args.side)
 	try:
 		sys.stdout.write(rendered)
 	except UnicodeEncodeError:
diff --git a/scripts/powerline-tmux b/scripts/powerline-tmux
index 51e01755..e9dde783 100755
--- a/scripts/powerline-tmux
+++ b/scripts/powerline-tmux
@@ -18,7 +18,7 @@ parser.add_argument('--ext', default='tmux')
 if __name__ == '__main__':
 	args = parser.parse_args()
 	powerline = Powerline(args.ext)
-	rendered = powerline.renderer.render(None, side=args.side)
+	rendered = powerline.renderer.render(side=args.side)
 	try:
 		sys.stdout.write(rendered)
 	except UnicodeEncodeError: