diff --git a/chrome/content/zotero-platform/mac/overlay.css b/chrome/content/zotero-platform/mac/overlay.css
index b943a16a29..46ab8276cf 100644
--- a/chrome/content/zotero-platform/mac/overlay.css
+++ b/chrome/content/zotero-platform/mac/overlay.css
@@ -152,7 +152,8 @@
 
 /* This seems to be necessary to center the tabs. Not sure why. */
 .zotero-editpane-tabs > tab:last-of-type > hbox .tab-text {
-	margin: 2px 9px 2px 9px !important;
+	margin-left: 9px !important;
+	margin-right: 9px !important;
 }
 
 .zotero-editpane-tabs > tab[selected=true] > hbox .tab-text {