diff --git a/src/less/header.less b/src/less/header.less
index 6b2ef6d1ba..ec75063b46 100644
--- a/src/less/header.less
+++ b/src/less/header.less
@@ -35,7 +35,7 @@
     margin-right: auto;
     border-color: gray transparent;
     border-style: solid;
-    border-width: 5px 5px 0 5px;
+    border-width: 0 5px 5px 5px;
     height: 0;
     width: 0;
 }
@@ -71,7 +71,7 @@
     margin-right: auto;
     border-color: gray transparent;
     border-style: solid;
-    border-width: 0 5px 5px 5px;
+    border-width: 5px 5px 0 5px;
     height: 0;
     width: 0;
 }
@@ -120,4 +120,4 @@
     border-style: solid;
     border-width: 6.5px 4.5px 0 4.5px;
     border-color: @buttonColor transparent transparent transparent;
-}
\ No newline at end of file
+}