diff --git a/components/style/themes/default.less b/components/style/themes/default.less
index f058bc2dc4..4015019739 100644
--- a/components/style/themes/default.less
+++ b/components/style/themes/default.less
@@ -71,6 +71,7 @@
 // https://github.com/ant-design/ant-design/issues/20210
 @line-height-base: 1.5715;
 @border-radius-base: 2px;
+@border-radius-sm: @border-radius-base;
 
 // vertical paddings
 @padding-lg: 24px; // containers