diff --git a/chrome/content/zotero/components/button.jsx b/chrome/content/zotero/components/button.jsx
index e9f4485c5e..41ea8a65b3 100644
--- a/chrome/content/zotero/components/button.jsx
+++ b/chrome/content/zotero/components/button.jsx
@@ -99,8 +99,23 @@ class Button extends PureComponent {
 		}
 
 		if (!this.props.isDisabled) {
-			attr.onMouseDown = this.handleMouseDown
+			attr.onMouseDown = (event) => {
+				// Hide tooltip on mousedown
+				if (this.title) {
+					window.Zotero_Tooltip.stop();
+				}
+				return this.handleMouseDown(event);
+			};
 			attr.onClick = this.handleClick
+			// Fake tooltip behavior as long as 'title' doesn't work for HTML-in-XUL elements
+			if (this.title) {
+				attr.onMouseOver = () => {
+					window.Zotero_Tooltip.start(this.title);
+				};
+				attr.onMouseOut = () => {
+					window.Zotero_Tooltip.stop();
+				};
+			}
 		}
 
 		return attr
diff --git a/chrome/content/zotero/tooltip.js b/chrome/content/zotero/tooltip.js
new file mode 100644
index 0000000000..9ad98c94ba
--- /dev/null
+++ b/chrome/content/zotero/tooltip.js
@@ -0,0 +1,78 @@
+/*
+    ***** BEGIN LICENSE BLOCK *****
+    
+    Copyright © 2020 Corporation for Digital Scholarship
+                     Vienna, Virginia, USA
+                     https://www.zotero.org
+    
+    This file is part of Zotero.
+    
+    Zotero is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+    
+    Zotero is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+    
+    You should have received a copy of the GNU Affero General Public License
+    along with Zotero.  If not, see <http://www.gnu.org/licenses/>.
+    
+    ***** END LICENSE BLOCK *****
+*/
+
+/**
+ * Fake tooltip implementation for HTML-in-XUL elements where neither 'title' nor 'tooltiptext' works
+ */
+// eslint-disable-next-line camelcase,no-unused-vars
+var Zotero_Tooltip = new function () {
+	// On macOS, the tooltip appears even if the mouse keeps moving over the element, but Mozilla
+	// shows it only once the mouse stops, so follow that as long as there are XUL elements.
+	const MOUSE_STOP_DELAY = 500;
+	
+	var text;
+	var timeoutID;
+	var x;
+	var y;
+	
+	/**
+	 * Start tracking the mouse and show a tooltip after it stops
+	 */
+	this.start = function (tooltipText) {
+		window.addEventListener('mousemove', handleMouseMove);
+		text = tooltipText;
+	};
+	
+	/**
+	 * Stop tracking the mouse and hide the tooltip if it's showing
+	 */
+	this.stop = function () {
+		window.removeEventListener('mousemove', handleMouseMove);
+		clearTimeout(timeoutID);
+		// Mozilla hides the tooltip as soon as the mouse leaves the element, which is also different
+		// from macOS behavior
+		hidePopup();
+	};
+	
+	function handleMouseMove(event) {
+		if (timeoutID) {
+			clearTimeout(timeoutID);
+		}
+		x = event.screenX;
+		y = event.screenY;
+		timeoutID = setTimeout(handleMouseStop, MOUSE_STOP_DELAY);
+	}
+	
+	function handleMouseStop() {
+		var tooltipElem = document.getElementById('fake-tooltip');
+		tooltipElem.setAttribute('label', text);
+		tooltipElem.openPopupAtScreen(x, y, false, null);
+	}
+	
+	function hidePopup() {
+		var tooltipElem = document.getElementById('fake-tooltip');
+		tooltipElem.hidePopup();
+	}
+};
diff --git a/chrome/content/zotero/zoteroPane.xul b/chrome/content/zotero/zoteroPane.xul
index 661dc59396..4d20c0ad9a 100644
--- a/chrome/content/zotero/zoteroPane.xul
+++ b/chrome/content/zotero/zoteroPane.xul
@@ -49,6 +49,7 @@
 	<script src="browser.js" type="application/javascript"/>
 	<script src="lookup.js"/>
 	<script src="locateMenu.js" type="application/javascript"/>
+	<script src="tooltip.js"/>
 	
 	<commandset id="mainCommandSet">
 		<command id="cmd_zotero_reportErrors" oncommand="ZoteroPane_Local.reportErrors();"/>
@@ -289,6 +290,8 @@
 					<menuitem class="menuitem-iconic zotero-menuitem-rename-from-parent" oncommand="ZoteroPane_Local.renameSelectedAttachmentsFromParents()"/>
 					<menuitem class="menuitem-iconic zotero-menuitem-reindex" oncommand="ZoteroPane_Local.reindexItem();"/>
 				</menupopup>
+				
+				<tooltip id="fake-tooltip"/>
 			</popupset>
 			
 			<hbox id="zotero-trees" flex="1">