diff --git a/style/components/dropdown.less b/style/components/dropdown.less
index b2ffe76eaa..34132a3dcd 100644
--- a/style/components/dropdown.less
+++ b/style/components/dropdown.less
@@ -46,6 +46,7 @@
     box-shadow: @box-shadow-base;
     background-clip: padding-box;
     border: 1px solid @border-color-base;
+    overflow: hidden;
 
     &-item,
     &-submenu-title {