diff --git a/ci/record_rep_weights.py b/ci/record_rep_weights.py
index cc7ea49ca8..320d38fd0b 100644
--- a/ci/record_rep_weights.py
+++ b/ci/record_rep_weights.py
@@ -1,6 +1,5 @@
 import requests
 import argparse
-from binascii import unhexlify
 from base64 import b32decode
 from binascii import hexlify, unhexlify
 
@@ -11,7 +10,7 @@
 parser.add_argument("--rpc", help="node rpc host:port",
                     default="http://[::1]:7076")
 parser.add_argument(
-    "--limit", help="percentage of the active supply represented", default=0.99)
+    "--limit", help="percentage of the active supply represented", default=0.99, type=float)
 parser.add_argument(
     "--cutoff", help="stop using bootstrap reps this many blocks before the current block height", default=250000, type=int)
 args = parser.parse_args()