diff --git a/src/services/OpenAPIParser.ts b/src/services/OpenAPIParser.ts
index 5894b0f4..303ae172 100644
--- a/src/services/OpenAPIParser.ts
+++ b/src/services/OpenAPIParser.ts
@@ -21,7 +21,6 @@ export class OpenAPIParser {
   specUrl?: string;
   spec: OpenAPISpec;
 
-  // private _refCounter: RefCounter = new RefCounter();
   private readonly allowMergeRefs: boolean = false;
 
   constructor(
diff --git a/src/utils/openapi.ts b/src/utils/openapi.ts
index e381cb70..7a48ad92 100644
--- a/src/utils/openapi.ts
+++ b/src/utils/openapi.ts
@@ -636,6 +636,8 @@ export const shortenHTTPVerb = verb =>
 export function isRedocExtension(key: string): boolean {
   const redocExtensions = {
     'x-circular-ref': true,
+    'x-parentRefs': true,
+    'x-refsStack': true,
     'x-code-samples': true, // deprecated
     'x-codeSamples': true,
     'x-displayName': true,