2 files changed, 14 insertions, 0 deletions
diff --git a/packages/browser/src/methods/startAttestation.test.ts b/packages/browser/src/methods/startAttestation.test.ts
index 539ffe5..faeca8b 100644
--- a/packages/browser/src/methods/startAttestation.test.ts
+++ b/packages/browser/src/methods/startAttestation.test.ts
@@ -38,6 +38,11 @@ const goodOpts1: PublicKeyCredentialCreationOptionsJSON = {
       name: 'username',
     },
     timeout: 1,
+    excludeCredentials: [{
+      id: 'authIdentifier',
+      type: 'public-key',
+      transports: ['internal'],
+    }],
   },
 };
 
@@ -64,6 +69,11 @@ test('should convert options before passing to navigator.credentials.create(...)
 
   expect(argsPublicKey.challenge).toEqual(toUint8Array(goodOpts1.publicKey.challenge));
   expect(argsPublicKey.user.id).toEqual(toUint8Array(goodOpts1.publicKey.user.id));
+  expect(argsPublicKey.excludeCredentials).toEqual([{
+    id: base64js.toByteArray('authIdentifier=='),
+    type: 'public-key',
+    transports: ['internal'],
+  }])
 
   done();
 });
diff --git a/packages/browser/src/methods/startAttestation.ts b/packages/browser/src/methods/startAttestation.ts
index c095670..14ffc53 100644
--- a/packages/browser/src/methods/startAttestation.ts
+++ b/packages/browser/src/methods/startAttestation.ts
@@ -7,6 +7,7 @@ import {
 import toUint8Array from '../helpers/toUint8Array';
 import toBase64String from '../helpers/toBase64String';
 import supportsWebauthn from '../helpers/supportsWebauthn';
+import toPublicKeyCredentialDescriptor from '../helpers/toPublicKeyCredentialDescriptor';
 
 /**
  * Begin authenticator "registration" via WebAuthn attestation
@@ -28,6 +29,9 @@ export default async function startAttestation(
       ...creationOptionsJSON.publicKey.user,
       id: toUint8Array(creationOptionsJSON.publicKey.user.id),
     },
+    excludeCredentials: creationOptionsJSON.publicKey.excludeCredentials.map(
+      toPublicKeyCredentialDescriptor,
+    ),
   };
 
   // Wait for the user to complete attestation