diff --git a/shared/naturalcrit/splitPane/splitPane.less b/shared/naturalcrit/splitPane/splitPane.less
index f8bc686de..567c1c6d0 100644
--- a/shared/naturalcrit/splitPane/splitPane.less
+++ b/shared/naturalcrit/splitPane/splitPane.less
@@ -56,6 +56,7 @@
 		&.lock{
 			.tooltipRight('Unlock cursor tracking between windows.');
 			top : 90px;
+			background: #666;
 		}
 		&.unlock{
 			.tooltipRight('Lock cursor tracking between windows.');