diff --git a/src/less/styles.less b/src/less/styles.less
index d4f4cb875..e2287b746 100644
--- a/src/less/styles.less
+++ b/src/less/styles.less
@@ -41,7 +41,9 @@
 }
 
 .rbc-header {
-  &:extend(.rbc-ellipsis);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
   padding: 0 3px;
   text-align: center;
   vertical-align: middle;