diff --git a/packages/pinia-orm/src/model/Model.ts b/packages/pinia-orm/src/model/Model.ts
index 181912cd4..b3112cf37 100644
--- a/packages/pinia-orm/src/model/Model.ts
+++ b/packages/pinia-orm/src/model/Model.ts
@@ -787,7 +787,9 @@ export class Model {
 
       if (mutator && typeof mutator !== 'function' && operation === 'set' && mutator.set) { keyValue = mutator.set(keyValue) }
 
-      if (cast && operation === 'set') { keyValue = cast.set(keyValue) }
+      if (cast && operation === 'set') {
+        keyValue = options.action === 'update' ? cast.get(keyValue) : cast.set(keyValue)
+      }
 
       this[key as keyof this] = this[key as keyof this] ?? keyValue
     }
@@ -1064,12 +1066,16 @@ export class Model {
   /**
    * Serialize the given object to JSON.
    */
-  protected serializeObject (value: {
-    [index: string]: number | string
-  }): object {
+  protected serializeObject (value: any): object {
     const obj: { [index: string]: number | string } = {}
 
-    for (const key in value) { obj[key] = this.serializeValue(value[key]) }
+    if (value.serialize && typeof value.serialize === 'function') {
+      return value.serialize(value)
+    }
+
+    for (const key in value) {
+      obj[key] = this.serializeValue(value[key])
+    }
 
     return obj
   }
diff --git a/packages/pinia-orm/src/query/Query.ts b/packages/pinia-orm/src/query/Query.ts
index 08f8e8e2a..2069c413a 100644
--- a/packages/pinia-orm/src/query/Query.ts
+++ b/packages/pinia-orm/src/query/Query.ts
@@ -836,15 +836,14 @@ export class Query<M extends Model = Model> {
     for (const id in elements) {
       const record = elements[id]
       const existing = currentData[id]
-      let model = existing
+      let model: M = existing
         ? Object.assign(this.hydrate(existing, { operation: 'set', action: 'update' }), record)
         : this.hydrate(record, { operation: 'set', action: 'save' })
-
       const isSaving = model.$self().saving(model, record)
       const isUpdatingOrCreating = existing ? model.$self().updating(model, record) : model.$self().creating(model, record)
       if (isSaving === false || isUpdatingOrCreating === false) { continue }
 
-      if (model.$isDirty()) { model = this.hydrate(model.$getAttributes(), { operation: 'set', action: existing ? 'update' : 'save' }) }
+      if (model.$isDirty()) { model = this.hydrate(model.$getAttributes(), { operation: 'set', action: 'update' }) }
 
       afterSavingHooks.push(() => model.$self().saved(model, record))
       afterSavingHooks.push(() => existing ? model.$self().updated(model, record) : model.$self().created(model, record))
diff --git a/packages/pinia-orm/tests/feature/casts/custom_casts.spec.ts b/packages/pinia-orm/tests/feature/casts/custom_casts.spec.ts
new file mode 100644
index 000000000..e99480338
--- /dev/null
+++ b/packages/pinia-orm/tests/feature/casts/custom_casts.spec.ts
@@ -0,0 +1,98 @@
+import { describe, expect, it } from 'vitest'
+
+import { CastAttribute, Model, useRepo } from '../../../src'
+import { Attr, Str } from '../../../src/decorators'
+import { assertState } from '../../helpers'
+
+describe('feature/casts/custom_casts', () => {
+  class House extends Model {
+    static entity = 'houses'
+
+    @Attr() id!: any
+    @Str('') name!: string
+    @Attr('{}') owner!: Person
+
+    static casts () {
+      return {
+        owner: PersonCast,
+      }
+    }
+  }
+
+  class Person {
+    firstname: string
+    lastname: string
+
+    constructor (firstname: string, lastname: string) {
+      this.firstname = firstname
+      this.lastname = lastname
+    }
+
+    static deserialize (fullname: string): Person {
+      const [firstname, lastname] = fullname.split(' ')
+      return new Person(firstname, lastname)
+    }
+
+    serialize (): string {
+      return `${this.firstname} ${this.lastname}`
+    }
+  }
+
+  class PersonCast extends CastAttribute {
+    get (value?: string): Person | undefined {
+      if (typeof value == 'string') {
+        return Person.deserialize(value)
+      }
+      return value
+    }
+
+    set (value?: Person): string | undefined {
+      if (value) {
+        return value.serialize()
+      }
+      return value
+    }
+  }
+
+  it('check custom cast insertion', () => {
+    const houseRepo = useRepo(House)
+
+    const returnedHouse = houseRepo.save({ id: 1, name: 'First', owner: new Person('John', 'Doe') })
+
+    expect(returnedHouse.owner.firstname).toEqual('John')
+    expect(returnedHouse.owner.lastname).toEqual('Doe')
+
+    const savedHouse = houseRepo.find(1)!
+
+    expect(savedHouse.owner.firstname).toEqual('John')
+    expect(savedHouse.owner.lastname).toEqual('Doe')
+
+    assertState({ houses: {
+      1: { id: 1, name: 'First', owner: 'John Doe' },
+    } })
+  })
+
+  it('check custom cast update', () => {
+    const houseRepo = useRepo(House)
+
+    houseRepo.save({ id: 1, name: 'First', owner: new Person('John', 'Doe') })
+
+    assertState({ houses: {
+      1: { id: 1, name: 'First', owner: 'John Doe' },
+    } })
+
+    const returnedHouse = houseRepo.save({ id: 1, owner: new Person('Foo', 'Bar') })
+
+    expect(returnedHouse.owner.firstname).toEqual('Foo')
+    expect(returnedHouse.owner.lastname).toEqual('Bar')
+
+    const updatedHouse = houseRepo.find(1)!
+
+    expect(updatedHouse.owner.firstname).toEqual('Foo')
+    expect(updatedHouse.owner.lastname).toEqual('Bar')
+
+    assertState({ houses: {
+      1: { id: 1, name: 'First', owner: 'Foo Bar' },
+    } })
+  })
+})