diff --git a/promenade/cli.py b/promenade/cli.py
index 5c6289c4..228db848 100644
--- a/promenade/cli.py
+++ b/promenade/cli.py
@@ -56,10 +56,7 @@ def genereate_certs(*, calico_etcd_service_ip, config_files, output_dir):
     debug = _debug()
     try:
         c = config.Configuration.from_streams(
-            debug=debug,
-            streams=config_files,
-            substitute=False,
-            validate=False)
+            debug=debug, streams=config_files, substitute=True, validate=False)
         g = generator.Generator(
             c, calico_etcd_service_ip=calico_etcd_service_ip)
         g.generate(output_dir)