diff --git a/components/menu/style/dark.less b/components/menu/style/dark.less
index 127e6843d8..2c75ade7a8 100644
--- a/components/menu/style/dark.less
+++ b/components/menu/style/dark.less
@@ -32,6 +32,7 @@
     border-color: @menu-dark-bg;
     border-bottom: 0;
     top: 0;
+    margin-top: 0;
   }
 
   &-dark&-horizontal > &-item > a:before {