diff --git a/letsencrypt/cli.py b/letsencrypt/cli.py
index 2e2ae1969..182e2bbc5 100644
--- a/letsencrypt/cli.py
+++ b/letsencrypt/cli.py
@@ -576,8 +576,8 @@ def create_parser(plugins, args):
     #for subparser in parser_run, parser_auth, parser_install:
     #    subparser.add_argument("domains", nargs="*", metavar="domain")
     helpful.add(None, "-d", "--domains", metavar="DOMAIN", action="append")
-    helpful.add(None, "-D", "--duplicate", dest="duplicate",
-        action="store_true",
+    helpful.add(
+        None, "-D", "--duplicate", dest="duplicate", action="store_true",
         help="Allow getting a certificate that duplicates an existing one")
 
     helpful.add_group(