diff --git a/.circleci/config.yml b/.circleci/config.yml
index eeb97b98..952e72bc 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -6,8 +6,9 @@ jobs:
       CIRCLE_ARTIFACTS: /tmp/circleci-artifacts
       CIRCLE_TEST_REPORTS: /tmp/circleci-test-results
       TOX_PY27: 2.7.13
-      TOX_PY35: 3.5.2
-      TOX_PY36: 3.6.1
+      TOX_PY35: 3.5.5
+      TOX_PY36: 3.6.5
+      TOX_PY37: 3.7-dev
     # To see the list of pre-built images that CircleCI provides for most
     # common languages see
     # https://circleci.com/docs/2.0/circleci-images/
@@ -42,7 +43,8 @@ jobs:
     - run: pyenv install -s $TOX_PY27
     - run: pyenv install -s $TOX_PY35
     - run: pyenv install -s $TOX_PY36
-    - run: pyenv local $TOX_PY27 $TOX_PY35 $TOX_PY36
+    - run: pyenv install -s $TOX_PY37
+    - run: pyenv local $TOX_PY27 $TOX_PY35 $TOX_PY36 $TOX_PY37
     # Save dependency cache
     - save_cache:
         key: txclient-{{ .Branch }}-{{ epoch }}
diff --git a/README.md b/README.md
index 3d62b250..00481c2e 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ Build transifex-client for Windows
 
 2.  Download and install [Python](https://www.python.org/downloads/windows/).
 
-    At this step choose the right version of python (2.7, 3.5 or 3.6) and x86 or x86-64 instruction set.
+    At this step choose the right version of python (2.7, 3.5, 3.6 or 3.7) and x86 or x86-64 instruction set.
 
     Make sure pip marked for installation(default for latest installers).
 
diff --git a/appveyor.yml b/appveyor.yml
index 112a94a7..524ff2b1 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -53,14 +53,14 @@ install:
 
   # Upgrade to the latest version of pip to avoid it displaying warnings
   # about it being out of date.
-  - "pip install --disable-pip-version-check --user --upgrade pip==9.0.3"
-  - "pip install pyinstaller"
+  - "python -m pip install --disable-pip-version-check --user --upgrade pip==9.0.3"
+  - "python -m pip install pyinstaller"
 
   # Set up the project in develop mode. If some dependencies contain
   # compiled extensions and are not provided as pre-built wheel packages,
   # pip will build them from source using the MSVC compiler matching the
   # target Python version and architecture
-  - pip install -e .
+  - "python -m pip install -e ."
 
 build_script:
   # Build the compiled extension
diff --git a/setup.py b/setup.py
index 7f4e02f2..5466d01b 100755
--- a/setup.py
+++ b/setup.py
@@ -7,37 +7,38 @@
 
 
 def get_file_content(filename):
-    with open(filename, 'r', encoding='UTF-8') as f:
+    with open(filename, "r", encoding="UTF-8") as f:
         return f.read()
 
 
 setup(
     name="transifex-client",
     version=txclib.__version__,
-    entry_points={'console_scripts': ['tx=txclib.cmdline:main']},
+    entry_points={"console_scripts": ["tx=txclib.cmdline:main"]},
     description="A command line interface for Transifex",
-    long_description=get_file_content('README.md'),
+    long_description=get_file_content("README.md"),
     author="Transifex",
     author_email="admin@transifex.com",
     url="https://www.transifex.com",
     license="GPLv2",
     dependency_links=[],
     setup_requires=[],
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,<3.7',
-    install_requires=get_file_content('requirements.txt').splitlines(),
+    python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,<3.8",
+    install_requires=get_file_content("requirements.txt").splitlines(),
     tests_require=["mock"],
     data_files=[],
     test_suite="tests",
     zip_safe=False,
-    packages=['txclib'],
+    packages=["txclib"],
     include_package_data=True,
     package_data={},
-    keywords=('translation', 'localization', 'internationalization',),
+    keywords=("translation", "localization", "internationalization",),
     classifiers=[
-        'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
     ],
 )
diff --git a/tox.ini b/tox.ini
index a37d5005..bd706486 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py{27,35,36}-{vanilla,pyopenssl}
+envlist = py{27,35,36,37}-{vanilla,pyopenssl}
 
 [testenv]
 deps =
diff --git a/txclib/__init__.py b/txclib/__init__.py
index abaeed58..4cbe5f72 100644
--- a/txclib/__init__.py
+++ b/txclib/__init__.py
@@ -1,4 +1,4 @@
 # -*- coding: utf-8 -*-
 
 # https://www.python.org/dev/peps/pep-0440/#examples-of-compliant-version-schemes
-__version__ = '0.13.3'
+__version__ = '0.13.4'