diff --git a/.circleci/config.yml b/.circleci/config.yml
index d3fee652..d77fa146 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -151,6 +151,7 @@ workflows:
                 - "3.7.2"
                 - "3.7.6"
                 - "3.8.5"
+                - "3.9.1"
       - dist:
           requires:
             - test
diff --git a/README.rst b/README.rst
index 73f69745..7385252d 100644
--- a/README.rst
+++ b/README.rst
@@ -43,8 +43,8 @@ Status
 Supported Python versions
 -------------------------
 
-Only Python 3.7 and 3.8. Python 3.6 and below will not work because we use some features introduced
-in Python 3.7.
+Only Python 3.7, 3.8 and 3.9. Python 3.6 and below will not work because we use some features
+introduced in Python 3.7.
 
 Quickstart
 ----------
diff --git a/setup.py b/setup.py
index 36f65e71..17f623e6 100755
--- a/setup.py
+++ b/setup.py
@@ -76,6 +76,7 @@ def get_version(*file_paths: Sequence[str]) -> str:
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
     ],
     description="""Python library for Servicio de Impuestos Internos (SII) of Chile.""",
     extras_require=extras_requirements,
@@ -87,7 +88,7 @@ def get_version(*file_paths: Sequence[str]) -> str:
     name='cl-sii',
     package_data=_package_data,
     packages=find_packages(exclude=['docs', 'tests*']),
-    python_requires='>=3.7, <3.9',
+    python_requires='>=3.7, <3.10',
     setup_requires=setup_requirements,
     test_suite='tests',
     tests_require=test_requirements,
diff --git a/tox.ini b/tox.ini
index 27abbb3a..445944fe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,6 +2,7 @@
 envlist =
     py37,
     py38,
+    py39,
 
 [testenv]
 setenv =
@@ -12,3 +13,4 @@ deps =
 basepython =
     py37: python3.7
     py38: python3.8
+    py39: python3.9