diff --git a/django_prbac/arbitrary.py b/django_prbac/arbitrary.py
index fd162c4..a3578cf 100644
--- a/django_prbac/arbitrary.py
+++ b/django_prbac/arbitrary.py
@@ -1,7 +1,9 @@
 import uuid
 from random import choice
 
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
+
+User = get_user_model()
 
 from django_prbac.models import *
 
diff --git a/django_prbac/migrations/0002_auto_20210930_1858.py b/django_prbac/migrations/0002_auto_20210930_1858.py
new file mode 100644
index 0000000..1b1eb24
--- /dev/null
+++ b/django_prbac/migrations/0002_auto_20210930_1858.py
@@ -0,0 +1,19 @@
+# Generated by Django 2.2.24 on 2021-09-30 18:58
+
+from django.db import migrations
+import django_jsonfield_backport.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('django_prbac', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='grant',
+            name='assignment',
+            field=django_jsonfield_backport.models.JSONField(blank=True, default=dict, help_text='Assignment from parameters (strings) to values (any JSON-compatible value)'),
+        ),
+    ]
diff --git a/django_prbac/models.py b/django_prbac/models.py
index 0f88fd3..a58d5b8 100644
--- a/django_prbac/models.py
+++ b/django_prbac/models.py
@@ -10,9 +10,8 @@
     def python_2_unicode_compatible(fn):
         return fn
 
-import jsonfield
-
 from django_prbac.fields import StringSetField
+from django_jsonfield_backport.models import JSONField
 
 
 __all__ = [
@@ -208,7 +207,7 @@ class Grant(ValidatingModel, models.Model):
         on_delete=models.CASCADE,
     )
 
-    assignment = jsonfield.JSONField(
+    assignment = JSONField(
         help_text='Assignment from parameters (strings) to values (any JSON-compatible value)',
         blank=True,
         default=dict,
diff --git a/django_prbac/tests/test_models.py b/django_prbac/tests/test_models.py
index ef0bb1d..f9621df 100644
--- a/django_prbac/tests/test_models.py
+++ b/django_prbac/tests/test_models.py
@@ -1,6 +1,6 @@
 from django.test import TestCase  # https://code.djangoproject.com/ticket/20913
 
-from django_prbac.models import Role
+from django_prbac.models import Role, Grant
 from django_prbac import arbitrary
 
 
@@ -95,6 +95,18 @@ def test_instantiated_to_role_smoke_test(self):
         grant = arbitrary.grant(to_role=superrole, assignment={'two': 'goodbye'})
         self.assertEqual(grant.instantiated_to_role({}).assignment, {})
 
+    def test_query_grant_assignments(self):
+        """
+        Test we can search grants using features in newer JSONField
+        """
+
+        user = arbitrary.role()
+        privilege = arbitrary.role(parameters={'thing'})
+        for thing in ['thingone', 'thingtwo']:
+            arbitrary.grant(to_role=privilege, from_role=user, assignment={'thing': thing})
+
+        assert Grant.objects.filter(from_role=user, assignment__thing='thingone').count() == 1
+
 
 class TestUserRole(TestCase):
 
diff --git a/setup.py b/setup.py
index 4bb77f0..deb0222 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,7 @@ def get_readme():
         # avoid django 2 <2.2.10 and django 3 < 3.0.7
         # https://github.com/advisories/GHSA-hmr4-m2h5-33qx
         'django>=2.2.13,!=3.0.0,!=3.0.1,!=3.0.2,!=3.0.3,!=3.0.4,!=3.0.5,!=3.0.6,<4',
-        'jsonfield>=1.0.3,<4',
+        'django-jsonfield-backport>=1.0,<2',
         'simplejson',
     ],
     classifiers=[