diff --git a/lib/utils/SchemaManager.js b/lib/utils/SchemaManager.js
index 31c19113..18a41bf6 100644
--- a/lib/utils/SchemaManager.js
+++ b/lib/utils/SchemaManager.js
@@ -89,7 +89,7 @@ export default class SchemaManager {
   buildMenuTree() {
     let tag2MethodMapping = new Map();
 
-    let definedTags = this._schema.tags;
+    let definedTags = this._schema.tags || [];
     // add tags into map to preserve order
     for (let tag of definedTags) {
       tag2MethodMapping.set(tag.name, {