diff --git a/chrome/content/zotero/components/tag-selector/tag-list.jsx b/chrome/content/zotero/components/tag-selector/tag-list.jsx
index 837310297c..865445eef0 100644
--- a/chrome/content/zotero/components/tag-selector/tag-list.jsx
+++ b/chrome/content/zotero/components/tag-selector/tag-list.jsx
@@ -139,6 +139,13 @@ class TagList extends React.PureComponent {
 		if (props.style.width < tagMaxWidth) {
 			delete props.style.width;
 		}
+		else {
+			// Setting this via props doesn't seem to work in XUL, but setting it on hover does.
+			// Hopefully in an HTML window we'll be able to just set 'title'.
+			props.onMouseOver = function (event) {
+				event.target.setAttribute('tooltiptext', tag.name);
+			};
+		}
 		
 		if (tag.color) {
 			props.style.color = tag.color;