diff --git a/src/framework/types.ts b/src/framework/types.ts
index 629b8c9a..57d33705 100644
--- a/src/framework/types.ts
+++ b/src/framework/types.ts
@@ -247,7 +247,7 @@ export namespace OpenAPIV3 {
   }
 
   export interface NonArraySchemaObject extends BaseSchemaObject {
-    type: NonArraySchemaObjectType;
+    type?: NonArraySchemaObjectType;
   }
 
   interface BaseSchemaObject {