Don't require --publickey, but print better error message.

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/check-sth.py b/tools/check-sth.py
index 0cdc031..dacd8e6 100755
--- a/tools/check-sth.py
+++ b/tools/check-sth.py
@@ -26,8 +26,8 @@ parser.add_argument('--cur-sth',
                     metavar='file',
                     default=DEFAULT_CUR_FILE,
                     help="File containing current STH (default=%s)" % DEFAULT_CUR_FILE)
-parser.add_argument('publickey', help='File containing the public key for the CT log')
 parser.add_argument('baseurl', help="Base URL for CT log")
+parser.add_argument('--publickey', default=None, metavar='file', help='Public key for the CT log')
 parser.add_argument('--cafile', default=None, metavar='file', help='File containing the CA cert')
 parser.add_argument('--allow-lag', action='store_true', help='Allow node to lag behind previous STH')
 parser.add_argument('--quiet-ok', action='store_true', help="Don't print status if OK")