diff --git a/calendar/templates/default/app.css b/calendar/templates/default/app.css
index ab90bbb489..b414373810 100644
--- a/calendar/templates/default/app.css
+++ b/calendar/templates/default/app.css
@@ -528,9 +528,6 @@ e.g. the div with class calendar_calTimeGrid is generated by the timeGridWidget
 }
 .calendar_calEventTooltip{
 	padding-left: 6px;
-	border-radius: 6px;
-	-moz-border-radius: 6px;
-	-webkit-border-radius: 6px;
 	max-height: 400px;
 	min-width: 25ex;
 	overflow: auto;
diff --git a/calendar/templates/pixelegg/app.css b/calendar/templates/pixelegg/app.css
index c881f171b7..c03448a9c5 100755
--- a/calendar/templates/pixelegg/app.css
+++ b/calendar/templates/pixelegg/app.css
@@ -816,9 +816,6 @@ e.g. the div with class calendar_calTimeGrid is generated by the timeGridWidget
   border-width: 1px;
 }
 .calendar_calEventTooltip {
-  -webkit-border-radius: 3px;
-  -moz-border-radius: 3px;
-  border-radius: 3px;
   max-height: 400px;
   overflow: auto;
 }
diff --git a/calendar/templates/pixelegg/app.less b/calendar/templates/pixelegg/app.less
index 87d6b094d2..8230dee272 100755
--- a/calendar/templates/pixelegg/app.less
+++ b/calendar/templates/pixelegg/app.less
@@ -947,7 +947,6 @@ e.g. the div with class calendar_calTimeGrid is generated by the timeGridWidget
 }
 
 .calendar_calEventTooltip{
-    .rounded(3px);
     max-height: 400px;
     overflow: auto;
 }