diff --git a/components/tree/style/rtl.less b/components/tree/style/rtl.less
index bc985c956b..7604ef60eb 100644
--- a/components/tree/style/rtl.less
+++ b/components/tree/style/rtl.less
@@ -56,7 +56,7 @@
   }
   // >>> Checkbox
   &-checkbox {
-    .@{tree-prefix-cls}-rtl& {
+    .@{tree-prefix-cls}-rtl & {
       margin: ((@tree-title-height - @checkbox-size) / 2) 0 0 8px;
     }
   }