diff --git a/webroot/rsrc/css/application/differential/revision-comment.css b/webroot/rsrc/css/application/differential/revision-comment.css
index ee243174d8..9fbb0660ec 100644
--- a/webroot/rsrc/css/application/differential/revision-comment.css
+++ b/webroot/rsrc/css/application/differential/revision-comment.css
@@ -14,6 +14,7 @@
 */
 .differential-haunt-mode-1 .differential-add-comment-panel,
 .differential-haunt-mode-2 .differential-add-comment-panel {
+  background-color: #fff;
   position: fixed;
   width: 100%;
   bottom: 0;