diff --git a/public/css/components/calendar.css b/public/css/components/calendar.css
index 4657bbb3f..9be771adf 100644
--- a/public/css/components/calendar.css
+++ b/public/css/components/calendar.css
@@ -203,8 +203,7 @@
 }
 
 .fhc-highlight-day {
-	border-width: 2px !important;
-	border-color: black !important;
+	box-shadow: inset 0 0 0 2px black !important;
 }
 
 .fhc-calendar-sm .fhc-calendar-month-page-day.active .no,