diff --git a/chrome/content/zotero-platform/mac/treesource-collection@2x.png b/chrome/content/zotero-platform/mac/treesource-collection@2x.png
new file mode 100644
index 000000000..c07acf5ff
Binary files /dev/null and b/chrome/content/zotero-platform/mac/treesource-collection@2x.png differ
diff --git a/chrome/content/zotero-platform/mac/treesource-search@2x.png b/chrome/content/zotero-platform/mac/treesource-search@2x.png
new file mode 100644
index 000000000..20b458aac
Binary files /dev/null and b/chrome/content/zotero-platform/mac/treesource-search@2x.png differ
diff --git a/chrome/skin/default/zotero/overlay.css b/chrome/skin/default/zotero/overlay.css
index 8e4f52b67..af53541a0 100644
--- a/chrome/skin/default/zotero/overlay.css
+++ b/chrome/skin/default/zotero/overlay.css
@@ -663,6 +663,10 @@
 	padding-right: 6px;
 }
 
+#zotero-tb-sync .toolbarbutton-icon {
+	max-width: 28px;
+}
+
 #zotero-tb-sync[status=animate] {
 	list-style-image: url(chrome://zotero/skin/arrow_rotate_animated.png);
 }