diff --git a/src/fake_mailer.ts b/src/fake_mailer.ts
index 22c33fb..c56a9cc 100644
--- a/src/fake_mailer.ts
+++ b/src/fake_mailer.ts
@@ -23,6 +23,7 @@ import type {
   MailerContract,
   MailerMessenger,
   MessageSearchOptions,
+  NormalizeConstructor,
   MessageComposeCallback,
 } from './types.js'
 
@@ -63,7 +64,7 @@ class MailsCollection {
    * Assert the mentioned mail was sent during the fake
    * mode
    */
-  assertSent<T extends typeof BaseMail>(
+  assertSent<T extends NormalizeConstructor<typeof BaseMail>>(
     mailConstructor: T,
     findFn?: (mail: InstanceType<T>) => boolean
   ) {
@@ -85,7 +86,7 @@ class MailsCollection {
    * Assert the mentioned mail was NOT sent during the fake
    * mode
    */
-  assertNotSent<T extends typeof BaseMail>(
+  assertNotSent<T extends NormalizeConstructor<typeof BaseMail>>(
     mailConstructor: T,
     findFn?: (mail: InstanceType<T>) => boolean
   ) {
@@ -112,8 +113,11 @@ class MailsCollection {
    * Assert the mentioned mail was sent for expected number
    * of times
    */
-  assertSentCount(mailConstructor: typeof BaseMail, count: number): void
-  assertSentCount(mailConstructor: typeof BaseMail | number, count?: number): void {
+  assertSentCount(mailConstructor: NormalizeConstructor<typeof BaseMail>, count: number): void
+  assertSentCount(
+    mailConstructor: NormalizeConstructor<typeof BaseMail> | number,
+    count?: number
+  ): void {
     if (typeof mailConstructor === 'number') {
       const actual = this.#sent.length
       const expected = mailConstructor
@@ -161,7 +165,7 @@ class MailsCollection {
    * Assert the mentioned mail was queued during the fake
    * mode
    */
-  assertQueued<T extends typeof BaseMail>(
+  assertQueued<T extends NormalizeConstructor<typeof BaseMail>>(
     mailConstructor: T,
     findFn?: (mail: InstanceType<T>) => boolean
   ) {
@@ -183,7 +187,7 @@ class MailsCollection {
    * Assert the mentioned mail was NOT queued during the fake
    * mode
    */
-  assertNotQueued<T extends typeof BaseMail>(
+  assertNotQueued<T extends NormalizeConstructor<typeof BaseMail>>(
     mailConstructor: T,
     findFn?: (mail: InstanceType<T>) => boolean
   ) {
@@ -210,8 +214,11 @@ class MailsCollection {
    * Assert the mentioned mail was sequeuednt for expected number
    * of times
    */
-  assertQueuedCount(mailConstructor: typeof BaseMail, count: number): void
-  assertQueuedCount(mailConstructor: typeof BaseMail | number, count?: number): void {
+  assertQueuedCount(mailConstructor: NormalizeConstructor<typeof BaseMail>, count: number): void
+  assertQueuedCount(
+    mailConstructor: NormalizeConstructor<typeof BaseMail> | number,
+    count?: number
+  ): void {
     if (typeof mailConstructor === 'number') {
       const actual = this.#queued.length
       const expected = mailConstructor
diff --git a/src/types.ts b/src/types.ts
index 28f4ec6..9c92c1f 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -498,3 +498,8 @@ export interface MailService
   extends MailManager<
     MailersList extends Record<string, MailManagerTransportFactory> ? MailersList : never
   > {}
+
+export type Constructor = abstract new (...args: any[]) => any
+export type NormalizeConstructor<T extends Constructor> = {
+  new (...args: any[]): InstanceType<T>
+} & Omit<T, 'constructor'>
diff --git a/tests/unit/fake_mailer/mails.spec.ts b/tests/unit/fake_mailer/mails.spec.ts
index 4847a4a..33e54fd 100644
--- a/tests/unit/fake_mailer/mails.spec.ts
+++ b/tests/unit/fake_mailer/mails.spec.ts
@@ -191,6 +191,41 @@ test.group('Fake mailer | mails | send', (group) => {
       return true
     })
   })
+
+  test('assert using mail class that accepts constructor arguments', async ({ assert, expectTypeOf }) => {
+    const emitter = new Emitter<MailEvents>(app)
+    const mailer = new FakeMailer('mailgun', emitter, {})
+    const { mails } = mailer
+
+    class VerifyEmail<UserId extends number> extends BaseMail {
+      from: string = 'foo@bar.com'
+      subject: string = 'Verify your email address'
+
+      constructor(public userId: UserId) {
+        super()
+      }
+
+      prepare() {
+        this.message.to('bar@baz.com')
+      }
+    }
+
+    const response = await mailer.send(new VerifyEmail(1))
+    assert.exists(response.messageId)
+    assert.deepEqual(response.envelope, { from: 'foo@bar.com', to: ['bar@baz.com'] })
+
+    mails.assertSent(VerifyEmail)
+    mails.assertSent(VerifyEmail, (mail) => {
+      expectTypeOf(mail).toMatchTypeOf<VerifyEmail<number>>
+      return mail.message.hasTo('bar@baz.com') && mail.message.hasFrom('foo@bar.com')
+    })
+
+    assert.throws(() => {
+      return mails.assertSent(VerifyEmail, (mail) => {
+        return mail.message.hasTo('bar@example.com')
+      })
+    }, 'Expected mail "VerifyEmail" was not sent')
+  })
 })
 
 test.group('Fake mailer | mails | sendLater', (group) => {