diff --git a/style/components/button.less b/style/components/button.less
index c698dc8644..18d82e8a7b 100644
--- a/style/components/button.less
+++ b/style/components/button.less
@@ -42,7 +42,7 @@
     > .@{iconfont-css-prefix} {
       top: -1px;
       font-size: 12px;
-      font-size: 10px \9; // ie8-9
+      font-size: ~"10px \9"; // ie8-9
       .scale(0.83);
 
       :root & {