diff --git a/app/javascript/styles/macaron/diff.scss b/app/javascript/styles/macaron/diff.scss
index be4f78a51..bf1e5b618 100644
--- a/app/javascript/styles/macaron/diff.scss
+++ b/app/javascript/styles/macaron/diff.scss
@@ -545,7 +545,8 @@ body.admin {
 .report-modal,
 .embed-modal,
 .error-modal,
-.onboarding-modal {
+.onboarding-modal,
+.compare-history-modal {
   background: $ui-base-color;
 }