diff --git a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/util.py b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/util.py
index 43070cf03..b635ee539 100644
--- a/letsencrypt-compatibility-test/letsencrypt_compatibility_test/util.py
+++ b/letsencrypt-compatibility-test/letsencrypt_compatibility_test/util.py
@@ -34,6 +34,8 @@ def create_le_config(parent_dir):
     os.mkdir(config["work_dir"])
     os.mkdir(config["logs_dir"])
 
+    config["domains"] = None
+
     return argparse.Namespace(**config)  # pylint: disable=star-args