diff --git a/mail/templates/default/app.css b/mail/templates/default/app.css
index 6aa604b19c..f6845df359 100644
--- a/mail/templates/default/app.css
+++ b/mail/templates/default/app.css
@@ -681,7 +681,7 @@ div.mailDisplayHeaders div.mail_extraEmails.visible {
 }
 
 .mailPreviewHeaders {
-    font-size: 0.875rem;
+	font-size: 87%;
 	position: relative;
 }