diff --git a/src/js/SchemaTextCompleter.js b/src/js/SchemaTextCompleter.js
index c0649a2a..ac3d98b8 100644
--- a/src/js/SchemaTextCompleter.js
+++ b/src/js/SchemaTextCompleter.js
@@ -178,7 +178,7 @@ export class SchemaTextCompleter {
                 }
               }
               return last
-            })
+            }, null)
             if (typeof option === 'string') {
               if (currentSuggestions[option]?.refs?.length) {
                 const mergedSuggestions = {}