diff --git a/chrome/content/zotero-platform/win/overlay.css b/chrome/content/zotero-platform/win/overlay.css
index d814488c9..14829ebf5 100644
--- a/chrome/content/zotero-platform/win/overlay.css
+++ b/chrome/content/zotero-platform/win/overlay.css
@@ -11,7 +11,9 @@
 	padding: 0;
 	border: 0;
 	background: transparent;
-	list-style-image: url("chrome://browser/skin/mainwindow-dropdown-arrow.png");
+	/* Mozilla file copied from chrome://browser/skin/mainwindow-dropdown-arrow.png
+	   for availability in Standalone */
+	list-style-image: url("chrome://zotero/skin/win/mainwindow-dropdown-arrow.png");
 	-moz-image-region: rect(0, 13px, 11px, 0);
 }
 
diff --git a/chrome/skin/default/zotero/win/mainwindow-dropdown-arrow.png b/chrome/skin/default/zotero/win/mainwindow-dropdown-arrow.png
new file mode 100644
index 000000000..7f5f55ef2
Binary files /dev/null and b/chrome/skin/default/zotero/win/mainwindow-dropdown-arrow.png differ