diff --git a/style/themes/default/custom.less b/style/themes/default/custom.less
index 9871a70bca..33165947b4 100644
--- a/style/themes/default/custom.less
+++ b/style/themes/default/custom.less
@@ -53,7 +53,7 @@
 @border-color-split     : #e9e9e9;        // split border inside a component
 
 // Buttons
-@btn-font-weight        : normal;
+@btn-font-weight        : 500;
 
 @btn-primary-color      : #fff;
 @btn-primary-bg         : @primary-color;