diff --git a/paypal/express/models.py b/paypal/express/models.py
index 2fc2ebcb..df4c863a 100644
--- a/paypal/express/models.py
+++ b/paypal/express/models.py
@@ -1,7 +1,7 @@
 import re
 
 from django.db import models
-from django.utils.encoding import python_2_unicode_compatible
+from six import python_2_unicode_compatible
 
 from paypal import base
 
diff --git a/paypal/payflow/models.py b/paypal/payflow/models.py
index c76a4a34..44931fb8 100644
--- a/paypal/payflow/models.py
+++ b/paypal/payflow/models.py
@@ -1,9 +1,9 @@
 import re
 
 from django.db import models
-from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
+from six import python_2_unicode_compatible
 
 from paypal import base
 from paypal.payflow import codes
diff --git a/requirements.txt b/requirements.txt
index 32dcb98b..c1906ba5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,3 +13,4 @@ django-extensions==3.0.9
 django-debug-toolbar==3.1.1
 flake8
 isort
+six
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 0db23417..f63bd32f 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
     packages=find_packages(exclude=['sandbox*', 'tests*']),
     include_package_data=True,
     install_requires=[
-        'django>=2.2,<2.3',
+        'django>=2.2,<=3.1',
         'paypal-checkout-serversdk>=1.0.1',
         'requests>=1.0',
         'django-localflavor'