diff --git a/userChrome.css b/userChrome.css
index 847e68c..22e4af8 100644
--- a/userChrome.css
+++ b/userChrome.css
@@ -634,6 +634,10 @@ tree-view[data-show-grouped-by-sort="true"] .card-layout.children *:hover {
 	border-color: #ececee !important;
 }
 
+#hdrReplyAllButton, #hdrReplyListButton {
+	border-radius: var(--button-border-radius) !important;
+}
+
 #hdrReplyAllButton .toolbarbutton-menubutton-button,
 #hdrReplyAllButton .toolbarbutton-menubutton-dropmarker,
 #hdrReplyListButton .toolbarbutton-menubutton-button,