diff --git a/docs/en-US/guide/nav.md b/docs/en-US/guide/nav.md
index 99072abd28..bc985e556f 100644
--- a/docs/en-US/guide/nav.md
+++ b/docs/en-US/guide/nav.md
@@ -32,7 +32,7 @@ there. Generally it can be categorized into 'sidebar navigation' and 'top naviga
 
 An appropriate navigation gives users a smooth experience, while an inappropriate
 one leads to confusion. Here are the differences between sidebar navigation and
-top navigation
+top navigation.
 
 ## Side Navigation