diff --git a/public/css/themes/modern.less b/public/css/themes/modern.less
index 5292a931ba..72e5ebf561 100644
--- a/public/css/themes/modern.less
+++ b/public/css/themes/modern.less
@@ -58,11 +58,6 @@ p {
 
 @btn-default-bg: @gray-lighter;
 @btn-default-color: @gray-darker;
-@btn-primary-border: darken(@brand-primary, 8%);
-@btn-success-border: darken(@brand-success, 8%);
-@btn-warning-border: darken(@brand-warning, 8%);
-@btn-danger-border: darken(@brand-danger, 8%);
-@btn-info-border: darken(@brand-info, 8%);
 
 .btn {
   padding: 10px 16px;