diff --git a/AUTHORS b/AUTHORS
index 2d3f80527..cf61dff0a 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -11,6 +11,7 @@ Abhishek Patel
 Adam Johnson
 Adam Zahradník
 Adheeth P Praveen
+Aibek Prenov
 Alan Crosswell
 Alan Rominger
 Alejandro Mantecon Guillen
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32dd1734c..214070dc7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * #1584 Fix IDP container in docker compose environment could not find templates and static files.
 * #1562 Fix: Handle AttributeError in IntrospectTokenView
 * #1583 Fix: Missing pt_BR translations
+* #1597 Fix: TypeError at /s/auth/o/token/
 <!--
 ### Security
 -->
diff --git a/oauth2_provider/oauth2_validators.py b/oauth2_provider/oauth2_validators.py
index db459a446..fc50352b8 100644
--- a/oauth2_provider/oauth2_validators.py
+++ b/oauth2_provider/oauth2_validators.py
@@ -867,12 +867,16 @@ def get_id_token_dictionary(self, token, token_handler, request):
         claims = self.get_oidc_claims(token, token_handler, request)
 
         expiration_time = timezone.now() + timedelta(seconds=oauth2_settings.ID_TOKEN_EXPIRE_SECONDS)
+        if request.user.last_login:
+            auth_time = int(dateformat.format(request.user.last_login, "U"))
+        else:
+            auth_time = int(timezone.now().timestamp())
         # Required ID Token claims
         claims.update(
             **{
                 "iss": self.get_oidc_issuer_endpoint(request),
                 "exp": int(dateformat.format(expiration_time, "U")),
-                "auth_time": int(dateformat.format(request.user.last_login, "U")),
+                "auth_time": auth_time,
                 "jti": str(uuid.uuid4()),
             }
         )
diff --git a/tests/test_oauth2_validators.py b/tests/test_oauth2_validators.py
index 14c74506e..ad23b64f1 100644
--- a/tests/test_oauth2_validators.py
+++ b/tests/test_oauth2_validators.py
@@ -60,6 +60,8 @@ def always_invalid_token():
 class TestOAuth2Validator(TransactionTestCase):
     def setUp(self):
         self.user = UserModel.objects.create_user("user", "test@example.com", "123456")
+        self.user.last_login = None
+        self.user.save()
         self.request = mock.MagicMock(wraps=Request)
         self.request.user = self.user
         self.request.grant_type = "not client"