diff --git a/lib/formattingTools.js b/lib/formattingTools.js
index 8118d5b4..d4550f8f 100644
--- a/lib/formattingTools.js
+++ b/lib/formattingTools.js
@@ -15,7 +15,8 @@ const s = require('./symbols');
 function gentitle(titles, type) {
   const [firsttitle] = titles;
   const lasttitle = [...titles].pop();
-  if (titles.length === 1) {
+
+  if (titles.length === 1 && firsttitle !== undefined) {
     return firsttitle;
   }
   if (lasttitle) {
@@ -24,6 +25,9 @@ function gentitle(titles, type) {
   if (typeof type === 'string') {
     return i18n`Untitled ${type} in ${firsttitle}`;
   }
+  if (firsttitle === undefined) {
+    return i18n`Untitled Schema`;
+  }
   return i18n`Untitled undefined type in ${firsttitle}`;
 }