diff --git a/src/django_pg_hll/fields.py b/src/django_pg_hll/fields.py
index 4d18fea..866f932 100644
--- a/src/django_pg_hll/fields.py
+++ b/src/django_pg_hll/fields.py
@@ -27,10 +27,10 @@ class HllField(BinaryField):
     }
 
     def __init__(self, *args, **kwargs):
-        self._log2m = kwargs.get('log2m', self.custom_params['log2m'])
-        self._regwidth = kwargs.get('regwidth', self.custom_params['regwidth'])
-        self._expthresh = kwargs.get('expthresh', self.custom_params['expthresh'])
-        self._sparseon = kwargs.get('sparseon', self.custom_params['sparseon'])
+        self._log2m = kwargs.pop('log2m', self.custom_params['log2m'])
+        self._regwidth = kwargs.pop('regwidth', self.custom_params['regwidth'])
+        self._expthresh = kwargs.pop('expthresh', self.custom_params['expthresh'])
+        self._sparseon = kwargs.pop('sparseon', self.custom_params['sparseon'])
 
         super(HllField, self).__init__(*args, **kwargs)
 
@@ -40,7 +40,7 @@ def deconstruct(self):
         # Only include kwarg if it's not the default
         for param_name, default in self.custom_params.items():
             if getattr(self, '_%s' % param_name) != default:
-                kwargs[name] = getattr(self, '_%s' % param_name)
+                kwargs[param_name] = getattr(self, '_%s' % param_name)
 
         return name, path, args, kwargs
 
diff --git a/tests/migrations/0001_initial.py b/tests/migrations/0001_initial.py
index 8ee5193..393fbaa 100644
--- a/tests/migrations/0001_initial.py
+++ b/tests/migrations/0001_initial.py
@@ -28,5 +28,15 @@ class Migration(migrations.Migration):
             options={
                 'abstract': False,
             }
+        ),
+        migrations.CreateModel(
+            name='TestConfiguredModel',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('hll_field', HllField(log2m=13, regwidth=2, expthresh=1, sparseon=0)),
+            ],
+            options={
+                'abstract': False,
+            }
         )
     ]
diff --git a/tests/models.py b/tests/models.py
index 596ec3c..cf541db 100644
--- a/tests/models.py
+++ b/tests/models.py
@@ -11,3 +11,7 @@ class TestModel(models.Model):
     hll_field = HllField()
     fk = models.ForeignKey(FKModel, null=True, blank=True, on_delete=models.CASCADE)
 
+
+class TestConfiguredModel(models.Model):
+    hll_field = HllField(log2m=13, regwidth=2, expthresh=1, sparseon=0)
+
diff --git a/tests/test_hll_field.py b/tests/test_hll_field.py
index 2fc7465..c614e09 100644
--- a/tests/test_hll_field.py
+++ b/tests/test_hll_field.py
@@ -12,7 +12,7 @@
 from django_pg_hll.bulk_update import HllConcatFunction
 
 from django_pg_hll.compatibility import django_pg_bulk_update_available
-from tests.models import TestModel, FKModel
+from tests.models import TestConfiguredModel, TestModel, FKModel
 
 
 class HllFieldTest(TestCase):
@@ -40,6 +40,14 @@ def test_combine_auto_parse(self):
     def test_create(self):
         TestModel.objects.create(hll_field=HllEmpty())
 
+    def test_create_custom_params(self):
+        with connection.cursor() as cursor:
+            cursor.execute('select hll_set_defaults(13,2,1,0);')
+            try:
+                TestConfiguredModel.objects.create(hll_field=HllEmpty())
+            finally:
+                cursor.execute('select hll_set_defaults(11,5,-1,1);')
+
     def test_migration(self):
         query = "SELECT hll_cardinality(hll_field) FROM tests_testmodel;"
         self.cursor.execute(query)