diff --git a/powerline/shell.py b/powerline/shell.py
index b887d323..aa04dc3d 100644
--- a/powerline/shell.py
+++ b/powerline/shell.py
@@ -62,6 +62,6 @@ def finish_args(args):
 	if args.config:
 		args.config = mergeargs((parsedotval(v) for v in args.config))
 	if args.theme_option:
-		args.theme_option = mergeargs((parsedotval(v) for v in args.config))
+		args.theme_option = mergeargs((parsedotval(v) for v in args.theme_option))
 	else:
 		args.theme_option = {}