diff --git a/django-stubs/db/models/fields/__init__.pyi b/django-stubs/db/models/fields/__init__.pyi
index 0058c31..9c87c7f 100644
--- a/django-stubs/db/models/fields/__init__.pyi
+++ b/django-stubs/db/models/fields/__init__.pyi
@@ -36,7 +36,7 @@ class BooleanField(Field):
     def __set__(self, instance, value: bool) -> None: ...
     def __get__(self, instance, owner) -> bool: ...
 
-class NullBooleanField(BooleanField):
+class NullBooleanField(Field):
     def __set__(self, instance, value: Optional[bool]) -> None: ...
     def __get__(self, instance, owner) -> Optional[bool]: ...