diff --git a/model_bakery/generators.py b/model_bakery/generators.py
index 159eb7b0..429e3fd8 100644
--- a/model_bakery/generators.py
+++ b/model_bakery/generators.py
@@ -20,7 +20,6 @@
     IntegerField,
     IPAddressField,
     ManyToManyField,
-    NullBooleanField,
     OneToOneField,
     PositiveIntegerField,
     PositiveSmallIntegerField,
@@ -87,6 +86,13 @@
     CIEmailField = None
     CITextField = None
 
+try:
+    # Deprecated since Django 3.1
+    from django.db.models import NullBooleanField
+except ImportError:
+    NullBooleanField = None
+
+
 try:
     # PostgreSQL-specific fields (only available when psycopg2 is installed)
     from django.contrib.postgres.fields.ranges import (
@@ -124,7 +130,6 @@ def gen_integer():
     OneToOneField: random_gen.gen_related,
     ManyToManyField: random_gen.gen_m2m,
     BooleanField: random_gen.gen_boolean,
-    NullBooleanField: random_gen.gen_boolean,
     IntegerField: _make_integer_gen_by_range(IntegerField),
     BigIntegerField: _make_integer_gen_by_range(BigIntegerField),
     SmallIntegerField: _make_integer_gen_by_range(SmallIntegerField),
@@ -185,6 +190,8 @@ def gen_integer():
     default_mapping[DateRangeField] = random_gen.gen_date_range
 if DateTimeRangeField:
     default_mapping[DateTimeRangeField] = random_gen.gen_datetime_range
+if NullBooleanField:
+    default_mapping[NullBooleanField] = random_gen.gen_boolean
 
 
 # Add GIS fields
diff --git a/tests/generic/models.py b/tests/generic/models.py
index eacbcacb..d299d0a0 100755
--- a/tests/generic/models.py
+++ b/tests/generic/models.py
@@ -228,7 +228,7 @@ def save(self, *args, **kwargs):
 
 class Classroom(models.Model):
     students = models.ManyToManyField(Person, null=True)
-    active = models.NullBooleanField()
+    active = models.BooleanField(null=True)
 
 
 class Store(models.Model):