diff --git a/src/less/lib/constant.less b/src/less/lib/constant.less
index 2ff6e6e60e..1eae029b3c 100644
--- a/src/less/lib/constant.less
+++ b/src/less/lib/constant.less
@@ -9,6 +9,7 @@
 @font-size-15: 15px;
 @font-size-16: 16px;
 @font-size-18: 18px;
+@font-size-20: 20px;
 @font-size-22: 22px;
 @font-size-24: 24px;
 @font-size-30: 30px;