diff --git a/chrome/content/zotero/elements/itemBox.js b/chrome/content/zotero/elements/itemBox.js
index 8142a92800..83971bd2fc 100644
--- a/chrome/content/zotero/elements/itemBox.js
+++ b/chrome/content/zotero/elements/itemBox.js
@@ -1573,8 +1573,7 @@
 				t.setAttribute('rows', 8);
 			}
 			// Add auto-complete for certain fields
-			else if (Zotero.ItemFields.isAutocompleteField(fieldName)
-					|| fieldName == 'creator') {
+			else if (field == 'creator' || Zotero.ItemFields.isAutocompleteField(fieldName)) {
 				t = document.createElement("input", { is: 'shadow-autocomplete-input' });
 				t.setAttribute('autocompletesearch', 'zotero');
 				
diff --git a/chrome/content/zotero/xpcom/data/itemFields.js b/chrome/content/zotero/xpcom/data/itemFields.js
index 176fd81ab0..b0ed5788f4 100644
--- a/chrome/content/zotero/xpcom/data/itemFields.js
+++ b/chrome/content/zotero/xpcom/data/itemFields.js
@@ -349,7 +349,11 @@ Zotero.ItemFields = new function() {
 	
 	
 	this.isAutocompleteField = function (field) {
-		field = this.getName(field);
+		var fieldName = this.getName(field);
+		if (!fieldName) {
+			Zotero.logError(`Can't check autocomplete for invalid field '${field}'`);
+			return false;
+		}
 		
 		var autoCompleteFields = [
 			'journalAbbreviation',
@@ -379,7 +383,7 @@ Zotero.ItemFields = new function() {
 			autoCompleteFields = autoCompleteFields.concat(add);
 		}
 		
-		return autoCompleteFields.indexOf(field) != -1;
+		return autoCompleteFields.includes(fieldName);
 	}