diff --git a/backend/routers/admin.py b/backend/routers/admin.py
index 4fa6f3e..75050ef 100644
--- a/backend/routers/admin.py
+++ b/backend/routers/admin.py
@@ -668,10 +668,11 @@ async def admin_setup_script(
     template_dir = Path(__file__).parent.parent / "templates_cert"
     jinja_env = Environment(loader=FileSystemLoader(str(template_dir)))
 
+    from urllib.parse import quote
     settings = get_settings()
     base_url = str(request.base_url).rstrip("/")
     ext = "ps1" if os == "windows" else "sh"
-    download_url = f"{base_url}/admin/api/script/download?domain={domain}&server_name={server_name}&os={os}"
+    download_url = f"{base_url}/admin/api/script/download?domain={quote(domain)}&server_name={quote(server_name)}&os={os}"
 
     template_name = "setup-cert.ps1.j2" if os == "windows" else "setup-cert.sh.j2"
     tpl = jinja_env.get_template(template_name)