diff --git a/README.md b/README.md
index 86894f2a6..d90bbebb5 100644
--- a/README.md
+++ b/README.md
@@ -1247,7 +1247,7 @@ import { mixed, InferType } from 'yup';
 let objectIdSchema = yup
   .mixed((input): input is ObjectId => input instanceof ObjectId)
   .transform((value: any, input, ctx) => {
-    if (ctx.typeCheck(value)) return value;
+    if (ctx.isType(value)) return value;
     return new ObjectId(value);
   });
 
diff --git a/src/object.ts b/src/object.ts
index 5b307b302..3aac8b94e 100644
--- a/src/object.ts
+++ b/src/object.ts
@@ -316,7 +316,11 @@ export default class ObjectSchema<
     }
 
     return next.withMutation((s: any) =>
-      s.setFields(nextFields, this._excludedEdges),
+      // XXX: excludes here is wrong
+      s.setFields(nextFields, [
+        ...this._excludedEdges,
+        ...schema._excludedEdges,
+      ]),
     );
   }
 
diff --git a/test/mixed.ts b/test/mixed.ts
index be55b5964..154169e8a 100644
--- a/test/mixed.ts
+++ b/test/mixed.ts
@@ -957,7 +957,7 @@ describe('Mixed Types ', () => {
         foo: array(number().integer()).required(),
         bar: string()
           .max(2)
-          .default(()=> 'a')
+          .default(() => 'a')
           .meta({ input: 'foo' })
           .label('str!')
           .oneOf(['a', 'b'])
@@ -966,7 +966,7 @@ describe('Mixed Types ', () => {
             is: 'entered',
             then: (s) => s.defined(),
           }),
-        baz: tuple([string(), number()])
+        baz: tuple([string(), number()]),
       });
     });
 
@@ -1070,7 +1070,7 @@ describe('Mixed Types ', () => {
                 oneOf: [],
                 notOneOf: [],
                 tests: [],
-              }
+              },
             ],
           },
         },
@@ -1182,7 +1182,7 @@ describe('Mixed Types ', () => {
                 oneOf: [],
                 notOneOf: [],
                 tests: [],
-              }
+              },
             ],
           },
         },
diff --git a/test/object.ts b/test/object.ts
index d18d11808..2911bf60e 100644
--- a/test/object.ts
+++ b/test/object.ts
@@ -1005,6 +1005,10 @@ describe('Object types', () => {
     await expect(
       schema.concat(object()).isValid({ a1: null }),
     ).resolves.toEqual(false);
+
+    await expect(
+      object().concat(schema).isValid({ a1: null }),
+    ).resolves.toEqual(false);
   });
 
   it('should handle nested conditionals', () => {