diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index a44f18fa..63ada29b 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.11.0
+current_version = 0.11.1
 commit = True
 tag = True
 
diff --git a/.circleci/config.yml b/.circleci/config.yml
index fcf3ad71..826646d8 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -34,7 +34,7 @@ jobs:
         type: string
 
     docker:
-      - image: python:<< parameters.python_version >>
+      - image: docker.io/library/python:<< parameters.python_version >>
 
     working_directory: ~/repo
 
@@ -79,7 +79,7 @@ jobs:
 
   dist:
     docker:
-      - image: python:3.7.2
+      - image: docker.io/library/python:3.8.5
 
     working_directory: ~/repo
 
@@ -119,7 +119,7 @@ jobs:
 
   deploy:
     docker:
-      - image: python:3.7.2
+      - image: docker.io/library/python:3.8.5
         environment:
           <<: *x-deploy-environment
 
@@ -148,10 +148,12 @@ workflows:
           matrix:
             parameters:
               python_version:
-                - "3.7.2"
-                - "3.7.6"
-                - "3.8.3"
-      - dist
+                - "3.7.9"
+                - "3.8.5"
+                - "3.9.1"
+      - dist:
+          requires:
+            - test
       - deploy:
           requires:
             - dist
diff --git a/HISTORY.rst b/HISTORY.rst
index cd246526..6f1faf38 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -3,6 +3,29 @@
 History
 -------
 
+0.11.1 (2020-12-15)
++++++++++++++++++++++++
+
+* (PR #140, 2020-09-15) config: Make CI 'dist' job depend on 'test' jobs
+* (PR #141, 2020-09-15) config: Update Python version used in CI jobs to 3.8.5
+* (PR #137, 2020-09-15) build(deps): bump keyring from 21.2.0 to 21.4.0
+* (PR #142, 2020-09-16) build(deps): bump mypy from 0.770 to 0.782
+* (PR #145, 2020-09-21) build(deps): bump setuptools from 46.1.3 to 50.3.0
+* (PR #146, 2020-09-23) build(deps): bump wheel from 0.34.2 to 0.35.1
+* (PR #147, 2020-09-23) requirements: update 'eight' (dependency of 'signxml')
+* (PR #149, 2020-09-24) build(deps): bump packaging from 20.3 to 20.4
+* (PR #150, 2020-09-28) build(deps): bump virtualenv from 20.0.26 to 20.0.31
+* (PR #157, 2020-11-12) requirements: Update 'flake8'
+* (PR #158, 2020-11-12) requirements: Update 'signxml'
+* (PR #161, 2020-12-15) Add support for Python 3.9
+* (PR #160, 2020-12-15) build(deps): bump cryptography from 2.9 to 3.3.1
+* (PR #162, 2020-12-15) config: Update Python 3.7 version to 3.7.9
+* (PR #156, 2020-12-15) build(deps): bump attrs from 19.3.0 to 20.3.0
+* (PR #151, 2020-12-15) build(deps): update djangorestframework requirement
+  from <3.11,>=3.10.3 to >=3.10.3,<3.13
+* (PR #163, 2020-12-15) requirements: update 'mypy' (test)
+* (PR #164, 2020-12-15) requirements: update 'tox' (test)
+
 0.11.0 (2020-09-15)
 +++++++++++++++++++++++
 
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/cl_sii/__init__.py b/cl_sii/__init__.py
index 6d1de686..4fb02dbc 100644
--- a/cl_sii/__init__.py
+++ b/cl_sii/__init__.py
@@ -5,4 +5,4 @@
 """
 
 
-__version__ = '0.11.0'
+__version__ = '0.11.1'
diff --git a/requirements/base.txt b/requirements/base.txt
index b26ffd96..27baa355 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -2,14 +2,14 @@
 # note: it is mandatory to register all dependencies of the required packages.
 
 # Required packages:
-cryptography==2.9
+cryptography==3.2
 defusedxml==0.6.0
 jsonschema==3.2.0
 lxml==4.5.0
 marshmallow==2.19.5
 pyOpenSSL==18.0.0
 pytz==2019.3
-signxml==2.8.0
+signxml==2.8.1
 
 # Packages dependencies:
 #   - cryptography:
@@ -31,11 +31,11 @@ signxml==2.8.0
 #       - lxml
 #       - pyOpenSSL
 #           - six
-attrs==19.3.0
+attrs==20.3.0
 certifi==2020.4.5.1
 cffi==1.14.0
-eight==0.4.2
-future==0.16.0
+eight==1.0.0
+future==0.18.2
 importlib-metadata==1.6.0; python_version<'3.8'
 pycparser==2.20
 pyrsistent==0.16.0
diff --git a/requirements/extras.txt b/requirements/extras.txt
index 2bed291f..dd5d96e8 100644
--- a/requirements/extras.txt
+++ b/requirements/extras.txt
@@ -2,7 +2,7 @@
 
 # Required packages:
 Django>=2.2.10,<3
-djangorestframework>=3.10.3,<3.11
+djangorestframework>=3.10.3,<3.13
 
 # Packages dependencies:
 #   - Django:
diff --git a/requirements/release.txt b/requirements/release.txt
index 84a17473..a9f00094 100644
--- a/requirements/release.txt
+++ b/requirements/release.txt
@@ -4,9 +4,9 @@
 
 # Required packages:
 bumpversion==0.5.3
-setuptools==46.1.3
+setuptools==50.3.0
 twine==3.1.1
-wheel==0.34.2
+wheel==0.35.1
 
 # Packages dependencies:
 #   - twine:
@@ -42,7 +42,7 @@ wheel==0.34.2
 # idna
 importlib-metadata==1.6.0
 # jeepney
-keyring==21.2.0
+keyring==21.4.0
 pkginfo==1.5.0.1
 # Pygments
 readme-renderer==25.0
diff --git a/requirements/test.txt b/requirements/test.txt
index f438c60c..4967c1e7 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -5,9 +5,9 @@
 # Required packages:
 codecov==2.1.9
 coverage==4.5.3
-flake8==3.7.9
-mypy==0.770
-tox==3.16.1
+flake8==3.8.4
+mypy==0.790
+tox==3.20.1
 
 # Packages dependencies:
 #   - codecov:
@@ -52,17 +52,17 @@ filelock==3.0.12
 importlib-metadata==1.6.0
 mccabe==0.6.1
 mypy-extensions==0.4.3
-packaging==20.3
+packaging==20.4
 pluggy==0.13.1
 py==1.8.1
-pycodestyle==2.5.0
-pyflakes==2.1.1
+pycodestyle==2.6.0
+pyflakes==2.2.0
 # pyparsing
 # requests
 # six
 toml==0.10.1
 typed-ast==1.4.1
-typing-extensions==3.7.4.2
+typing-extensions==3.7.4.3
 # urllib3
-virtualenv==20.0.26
+virtualenv==20.0.31
 # zipp
diff --git a/scripts/clean_dte_xml_file.py b/scripts/clean_dte_xml_file.py
index 08488d2f..e790a714 100755
--- a/scripts/clean_dte_xml_file.py
+++ b/scripts/clean_dte_xml_file.py
@@ -91,12 +91,12 @@ def main_dir_files(input_files_dir_path: str) -> None:
             input_file_path=input_file_path,
             output_file_path=output_file_path)
 
-        print(f"Difference between input and output files:")
+        print("Difference between input and output files:")
         diff_line = None
         for diff_line in file_bytes_diff_gen:
             print(diff_line)
         if diff_line is None:
-            print(f"No difference.")
+            print("No difference.")
 
 
 if __name__ == '__main__':
diff --git a/setup.py b/setup.py
old mode 100755
new mode 100644
index 36f65e71..f406d9a0
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@ def get_version(*file_paths: Sequence[str]) -> str:
 history = open('HISTORY.rst').read().replace('.. :changelog:', '')
 
 requirements = [
-    'cryptography>=2.8,<3',
+    'cryptography>=2.8,<4',
     'defusedxml>=0.6.0,<1',
     'jsonschema>=3.1.1',
     'lxml>=4.5.0,<5',
@@ -35,7 +35,7 @@ def get_version(*file_paths: Sequence[str]) -> str:
 
 extras_requirements = {
     'django': ['Django>=2.2.10,<3'],
-    'djangorestframework': ['djangorestframework>=3.10.3,<3.11'],
+    'djangorestframework': ['djangorestframework>=3.10.3,<3.13'],
 }
 
 setup_requirements = [
@@ -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