diff --git a/chrome/content/zotero/collectionViewItemTree.jsx b/chrome/content/zotero/collectionViewItemTree.jsx
index 30ad42f7c8..fd6cf7d78a 100644
--- a/chrome/content/zotero/collectionViewItemTree.jsx
+++ b/chrome/content/zotero/collectionViewItemTree.jsx
@@ -1291,7 +1291,7 @@ class CollectionViewItemTree extends ItemTree {
 	_getRowData(index) {
 		var treeRow = this.getRow(index);
 		if (!treeRow) {
-			throw new Error(`Attempting to get row data for a non-existant tree row ${index}`);
+			throw new Error(`Attempting to get row data for a non-existent tree row ${index}`);
 		}
 		let itemID = treeRow.id;
 
diff --git a/chrome/content/zotero/itemTree.jsx b/chrome/content/zotero/itemTree.jsx
index 4bbe9be9e6..2b22a741b3 100644
--- a/chrome/content/zotero/itemTree.jsx
+++ b/chrome/content/zotero/itemTree.jsx
@@ -2362,7 +2362,7 @@ var ItemTree = class ItemTree extends LibraryTree {
 	_getRowData(index) {
 		var treeRow = this.getRow(index);
 		if (!treeRow) {
-			throw new Error(`Attempting to get row data for a non-existant tree row ${index}`);
+			throw new Error(`Attempting to get row data for a non-existent tree row ${index}`);
 		}
 		var itemID = treeRow.id;