diff --git a/packages/core/src/resolvers/ref.ts b/packages/core/src/resolvers/ref.ts
index 52514ebe0..c6b28ae8c 100644
--- a/packages/core/src/resolvers/ref.ts
+++ b/packages/core/src/resolvers/ref.ts
@@ -69,10 +69,17 @@ function getSchema<Schema extends ComponentObject = ComponentObject>(
 } {
   const refInfo = getRefInfo(schema.$ref, context);
 
-  const { specKey, refPaths } = refInfo;
+  const { specKey, refPaths = [] } = refInfo;
 
-  const schemaByRefPaths: Schema | undefined =
-    refPaths && get(context.specs[specKey || context.specKey], refPaths);
+  let schemaByRefPaths: Schema | undefined = get(
+    context.specs[context.specKey],
+    refPaths,
+  );
+  if (!schemaByRefPaths) {
+    schemaByRefPaths = context.specs?.[
+      specKey || context.specKey
+    ] as unknown as Schema;
+  }
   if (isReference(schemaByRefPaths)) {
     return getSchema(schemaByRefPaths, context);
   }
diff --git a/packages/core/src/utils/assertion.ts b/packages/core/src/utils/assertion.ts
index 316afdadc..2e4f8efc6 100644
--- a/packages/core/src/utils/assertion.ts
+++ b/packages/core/src/utils/assertion.ts
@@ -9,7 +9,7 @@ import { extname } from './path';
  * @param property
  */
 export const isReference = (property: any): property is ReferenceObject => {
-  return Boolean(property.$ref);
+  return Boolean(property?.$ref);
 };
 
 export const isDirectory = (path: string) => {