diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..10149e1
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,25 @@
+name: Test avista
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.8]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install tox tox-gh-actions
+    - name: Test with tox
+      run: tox
diff --git a/setup.py b/setup.py
index 8cf3f86..3947c25 100644
--- a/setup.py
+++ b/setup.py
@@ -1,32 +1,20 @@
-from setuptools import setup, find_packages
+from setuptools import setup, find_namespace_packages
 import re
 
-VERSIONFILE = "src/avista/_version.py"
-verstr = "unknown"
-try:
-    verstrline = open(VERSIONFILE, "rt").read()
-    VSRE = r"^__version__ = ['\"]([^'\"]*)['\"]"
-    mo = re.search(VSRE, verstrline, re.M)
-    if mo:
-        verstr = mo.group(1)
-except EnvironmentError:
-    print("unable to find version in %s" % (VERSIONFILE,))
-    raise RuntimeError("if %s exists, it is required to be well-formed" % (VERSIONFILE,))
-
 setup(
     name='avista',
-    version=verstr,
+    use_scm_version=True,
     description='Library for controlling A/V devices',
     author='James Muscat',
     author_email='jamesremuscat@gmail.com',
     url='https://github.com/jamesremuscat/avista',
-    packages=find_packages('src', exclude=["*.tests"]),
+    packages=find_namespace_packages('src', exclude=["*.tests"]),
     package_dir={'': 'src'},
     long_description="""\
     avista is a library for controlling A/V devices such as video switchers. It
     is a modernised rewrite of the avx library from the same author.
     """,
-    setup_requires=[],
+    setup_requires=['setuptools_scm'],
     tests_require=[],
     install_requires=[
         'autobahn[twisted]',
diff --git a/src/avista/_version.py b/src/avista/_version.py
deleted file mode 100644
index b8023d8..0000000
--- a/src/avista/_version.py
+++ /dev/null
@@ -1 +0,0 @@
-__version__ = '0.0.1'
diff --git a/src/avista/devices/blackmagic/atem/commands/mix_effects.py b/src/avista/devices/blackmagic/atem/commands/mix_effects.py
index f532e85..34ccf9e 100644
--- a/src/avista/devices/blackmagic/atem/commands/mix_effects.py
+++ b/src/avista/devices/blackmagic/atem/commands/mix_effects.py
@@ -483,7 +483,7 @@ def calculate(cls, obj):
         'index' / Int8ub,
         'key_index' / Int8ub,
         'type' / EnumAdapter(KeyType)(Default(Int8ub, 0)),
-        'fly_enabled' / Flag,
+        'fly_enabled' / Default(Flag, False),
         Padding(3)
     )
 
diff --git a/src/avista/devices/blackmagic/atem/commands/tests/__init__.py b/src/avista/devices/blackmagic/atem/commands/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/avista/devices/blackmagic/atem/commands/tests/test_mix_effects.py b/src/avista/devices/blackmagic/atem/commands/tests/test_mix_effects.py
new file mode 100644
index 0000000..0fd9335
--- /dev/null
+++ b/src/avista/devices/blackmagic/atem/commands/tests/test_mix_effects.py
@@ -0,0 +1,10 @@
+from avista.devices.blackmagic.atem.commands.mix_effects import SetKeyerType
+from avista.devices.blackmagic.atem.constants import KeyType
+
+
+def test_set_keyer_type():
+    cmd = SetKeyerType(index=0, key_index=1, type=KeyType.PATTERN)
+    b = cmd.to_bytes()
+
+    assert b[0:4] == b'CKTp'
+    assert b[4] == 0x80  # = binary 10000000
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..c89c72c
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,19 @@
+# tox (https://tox.readthedocs.io/) is a tool for running tests
+# in multiple virtualenvs. This configuration file will run the
+# test suite on all supported python versions. To use it, "pip install tox"
+# and then run "tox" from this directory.
+
+[tox]
+envlist = py38
+
+[testenv]
+deps =
+    pytest
+    autobahn[twisted]
+    construct
+commands =
+    pytest --import-mode=importlib
+
+[gh-actions]
+python =
+    3.8: py38