diff --git a/chrome/content/zotero/bindings/itembox.xml b/chrome/content/zotero/bindings/itembox.xml
index 40b66fd0b5..b1f961e3ca 100644
--- a/chrome/content/zotero/bindings/itembox.xml
+++ b/chrome/content/zotero/bindings/itembox.xml
@@ -1824,6 +1824,8 @@
 					var elem;
 					var [field, creatorIndex, creatorField] = fieldName.split('-');
 					var newVal;
+
+					creatorIndex = parseInt(creatorIndex);
 					
 					// Creator fields
 					if (field == 'creator') {