diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9aae2c7..9be7e56 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -7,7 +7,7 @@ repos:
       - id: end-of-file-fixer
       - id: trailing-whitespace
   - repo: https://github.com/myint/autoflake
-    rev: v1.4
+    rev: v2.0.0
     hooks:
       - id: autoflake
         args:
@@ -15,7 +15,7 @@ repos:
           - --remove-unused-variables
           - --remove-all-unused-imports
   - repo: https://github.com/pycqa/isort
-    rev: 5.10.1
+    rev: 5.12.0
     hooks:
       - id: isort
   - repo: https://github.com/psf/black
@@ -23,7 +23,7 @@ repos:
     hooks:
       - id: black
         language_version: python3 # Should be a command that runs python3.6+
-  - repo: https://gitlab.com/pycqa/flake8
-    rev: '3.9.2'
+  - repo: https://github.com/PyCQA/flake8
+    rev: 6.0.0
     hooks:
       - id: flake8
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f90ba9..a353164 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,15 @@
 Changelog
 =========
 
+1.0.3
+-----
+
+Fixes:
+
+- Fail to run migration script for django 4
+- Fail to run migration script when duplicated idempotency_key exists
+
+
 1.0.2
 -----
 
diff --git a/rest_framework_idempotency_key/__version__.py b/rest_framework_idempotency_key/__version__.py
index a6221b3..3f6fab6 100644
--- a/rest_framework_idempotency_key/__version__.py
+++ b/rest_framework_idempotency_key/__version__.py
@@ -1 +1 @@
-__version__ = '1.0.2'
+__version__ = '1.0.3'
diff --git a/rest_framework_idempotency_key/migrations/0003_remove_user.py b/rest_framework_idempotency_key/migrations/0003_remove_user.py
index eefd241..d3a818c 100644
--- a/rest_framework_idempotency_key/migrations/0003_remove_user.py
+++ b/rest_framework_idempotency_key/migrations/0003_remove_user.py
@@ -3,6 +3,16 @@
 from django.db import migrations, models
 
 
+def remove_duplicated_records(apps, schema_editor):
+    IdempotencyKey = apps.get_model('rest_framework_idempotency_key', 'IdempotencyKey')
+    existed_keys = set()
+    for id_key in IdempotencyKey.objects.all():
+        if id_key.idempotency_key in existed_keys:
+            id_key.delete()
+        else:
+            existed_keys.add(id_key.idempotency_key)
+
+
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -10,14 +20,20 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RemoveField(
+        migrations.RunPython(remove_duplicated_records, migrations.RunPython.noop),
+        migrations.AlterField(
             model_name='idempotencykey',
             name='user',
+            field=models.IntegerField(null=True),
         ),
         migrations.RemoveConstraint(
             model_name='idempotencykey',
             name='Unique IdempotencyKey (user, idempotency_key)',
         ),
+        migrations.RemoveField(
+            model_name='idempotencykey',
+            name='user',
+        ),
         migrations.AddConstraint(
             model_name='idempotencykey',
             constraint=models.UniqueConstraint(
diff --git a/setup.cfg b/setup.cfg
index e4ca040..68efbe5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,8 +1,5 @@
 [flake8]
-extend-ignore=
-    E203, # See https://github.com/PyCQA/pycodestyle/issues/373
-    E501, # style related, follow black
-    W503, # style related, follow black
+extend-ignore= E203,E501,W503
 max-line-length = 120
 max-complexity = 100