diff --git a/npm_install.py b/npm_install.py
index b035ee4..1f3dd0d 100644
--- a/npm_install.py
+++ b/npm_install.py
@@ -211,7 +211,7 @@ def sync_backup_nginx_conf():
                 print(f"Warning: sync failed for {p} -> {target}: {e}")
 
 
-def _setup_certbot_venv(venv_dir: Path = Path("/opt/certbot")):
+def setup_certbot_venv(venv_dir: Path = Path("/opt/certbot")):
     try:
         apt_try_install([
             "python3-venv", "python3-dev", "gcc", "libffi-dev", "libssl-dev",
@@ -1184,7 +1184,7 @@ def main():
     install_node_and_yarn(args.nodejs_pkg)
     ensure_user_and_dirs()
     create_sudoers_for_npm()
-    _setup_certbot_venv()
+    setup_certbot_venv()
 
     npm_app_version = deploy_npm_app(args.npm_version)