diff --git a/chrome/content/zotero-platform/mac/overlay.css b/chrome/content/zotero-platform/mac/overlay.css
index 04c1724c42..120e43931e 100644
--- a/chrome/content/zotero-platform/mac/overlay.css
+++ b/chrome/content/zotero-platform/mac/overlay.css
@@ -112,8 +112,11 @@
 }
 
 #zotero-view-tabbox > tabs {
-	-moz-appearance: toolbar; 
-	padding: 4px 0 4px 0;
+	background: -moz-linear-gradient(top, #f2f2f2, #cccccc);
+	border-style: solid;
+	border-width: 0 0 1px 0;
+	border-color: #5e5e5e;
+	padding: 2px 0 2px 0;
 }
 
 #zotero-view-tabbox > tabs > tab > hbox {