diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index 54cd3ac811..e76f6b82a1 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -174,8 +174,8 @@ var ZoteroPane = new function () {
 	function setUpKeyboardNavigation() {
 		let collectionTreeToolbar = document.getElementById("zotero-toolbar-collection-tree");
 		let itemTreeToolbar = document.getElementById("zotero-toolbar-item-tree");
-		// Plugins append their toolbar buttons after Zotero's built-in controls.
-		// Read the current buttons for each key event so installation needs no registration.
+		// Plugins can opt into keyboard focus with tabindex=0 on an appended
+		// toolbarbutton. Read the current buttons for each key event.
 		let pluginButtons = () => [...document.querySelectorAll(
 			'#zotero-items-toolbar > toolbarbutton[tabindex="0"]'
 		)].filter(button => !button.disabled && !button.hidden
@@ -408,7 +408,7 @@ var ZoteroPane = new function () {
 					ShiftTab: () => document.getElementById('zotero-tb-collections-search').click()
 				},
 				'zotero-tb-note-add': {
-					ArrowNext: () => pluginButtons()[0] || null,
+					ArrowNext: () => null,
 					ArrowPrevious: () => document.getElementById("zotero-tb-attachment-add"),
 					Tab: () => document.getElementById("zotero-tb-search").focus(),
 					ShiftTab: () => document.getElementById('zotero-tb-collections-search').click()
@@ -438,8 +438,7 @@ var ZoteroPane = new function () {
 			if (pluginButtons().includes(event.target)) {
 				actionsMap[event.target.id] = {
 					ArrowNext: () => adjacentPluginButton(event.target, 1) || null,
-					ArrowPrevious: () => adjacentPluginButton(event.target, -1)
-						|| document.getElementById('zotero-tb-note-add'),
+					ArrowPrevious: () => adjacentPluginButton(event.target, -1) || null,
 					Tab: () => adjacentPluginButton(event.target, 1)
 						|| itemTree.querySelector(".virtualized-table"),
 					ShiftTab: () => adjacentPluginButton(event.target, -1)
diff --git a/test/tests/zoteroPaneTest.js b/test/tests/zoteroPaneTest.js
index 413d310ff6..87e63e8574 100644
--- a/test/tests/zoteroPaneTest.js
+++ b/test/tests/zoteroPaneTest.js
@@ -1930,10 +1930,11 @@ describe("ZoteroPane", function () {
 				doc.activeElement.dispatchEvent(shiftTab);
 				assert.equal(doc.activeElement, buttons[0]);
 				doc.activeElement.dispatchEvent(shiftTab);
-				assert.include(
-					['zotero-tb-toggle-item-pane-stacked', 'zotero-tb-search-advanced-button'],
-					doc.activeElement.id
-				);
+				let toggleHidden = paneToggle.disabled || paneToggle.hidden
+					|| paneToggle.parentNode.hidden
+					|| win.getComputedStyle(paneToggle).display === 'none';
+				assert.equal(doc.activeElement.id, toggleHidden
+					? 'zotero-tb-search-advanced-button' : paneToggle.id);
 				doc.getElementById('zotero-tb-lookup').focus();
 				doc.activeElement.dispatchEvent(tab);
 				assert.equal(doc.activeElement.id, 'zotero-tb-search-textbox');
@@ -1943,6 +1944,9 @@ describe("ZoteroPane", function () {
 
 				doc.getElementById('zotero-tb-note-add').focus();
 				doc.activeElement.dispatchEvent(rightArrow);
+				assert.equal(doc.activeElement.id, 'zotero-tb-note-add');
+				buttons[0].focus();
+				doc.activeElement.dispatchEvent(leftArrow);
 				assert.equal(doc.activeElement, buttons[0]);
 				doc.activeElement.dispatchEvent(rightArrow);
 				assert.equal(doc.activeElement, buttons[1]);
@@ -1952,6 +1956,14 @@ describe("ZoteroPane", function () {
 				buttons[0].hidden = true;
 				paneToggle.dispatchEvent(tab);
 				assert.equal(doc.activeElement, buttons[1]);
+				buttons[0].hidden = false;
+				buttons[0].disabled = true;
+				paneToggle.dispatchEvent(tab);
+				assert.equal(doc.activeElement, buttons[1]);
+				buttons[0].disabled = false;
+				buttons[0].style.display = 'none';
+				paneToggle.dispatchEvent(tab);
+				assert.equal(doc.activeElement, buttons[1]);
 			}
 			finally {
 				buttons.forEach(button => button.remove());