diff --git a/docs/ssr.md b/docs/ssr.md
index 3e3b9a579..2b0d19a47 100644
--- a/docs/ssr.md
+++ b/docs/ssr.md
@@ -118,7 +118,7 @@ var renderer = new Renderer({
   }
 })
 
-renderer.renderToString(url)
+renderer.renderToString()
   .then(html => {})
   .catch(err => {})
 ```