diff --git a/modules/ooui/styles/mw.echo.ui.BundledNotificationGroupWidget.less b/modules/ooui/styles/mw.echo.ui.BundledNotificationGroupWidget.less
index 34e7a67b3..18fb016cf 100644
--- a/modules/ooui/styles/mw.echo.ui.BundledNotificationGroupWidget.less
+++ b/modules/ooui/styles/mw.echo.ui.BundledNotificationGroupWidget.less
@@ -19,6 +19,7 @@
 	.mw-echo-ui-notificationItemWidget {
 		padding: 0.5em;
 		border: 1px solid #DDDDDD;
+		box-sizing: border-box;
 
 		&:not(:last-child) {
 			border-bottom: 0;
diff --git a/modules/ooui/styles/mw.echo.ui.NotificationItemWidget.less b/modules/ooui/styles/mw.echo.ui.NotificationItemWidget.less
index d9be2c9d4..58af9c49c 100644
--- a/modules/ooui/styles/mw.echo.ui.NotificationItemWidget.less
+++ b/modules/ooui/styles/mw.echo.ui.NotificationItemWidget.less
@@ -90,7 +90,7 @@
 	// Table layout only for the content inside bundles
 	&-bundle {
 		display: table;
-		width: ~"calc( 100% - " @bundle-group-padding ~");";
+		width: 100%;
 
 		.mw-echo-ui-notificationItemWidget-content {
 			display: table-row;