diff --git a/poetry.lock b/poetry.lock
index 53fbe8a..4ed3fcf 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -241,7 +241,7 @@ python-versions = ">=3.6,<4.0"
 
 [[package]]
 name = "cryptography"
-version = "3.1.1"
+version = "3.2.1"
 description = "cryptography is a package which provides cryptographic recipes and primitives to Python developers."
 category = "main"
 optional = false
@@ -252,11 +252,11 @@ cffi = ">=1.8,<1.11.3 || >1.11.3"
 six = ">=1.4.1"
 
 [package.extras]
-docs = ["sphinx (>=1.6.5,<1.8.0 || >1.8.0,<3.1.0 || >3.1.0,<3.1.1 || >3.1.1)", "sphinx-rtd-theme"]
+docs = ["sphinx (>=1.6.5,!=1.8.0,!=3.1.0,!=3.1.1)", "sphinx-rtd-theme"]
 docstest = ["doc8", "pyenchant (>=1.6.11)", "twine (>=1.12.0)", "sphinxcontrib-spelling (>=4.0.1)"]
 pep8test = ["black", "flake8", "flake8-import-order", "pep8-naming"]
 ssh = ["bcrypt (>=3.1.5)"]
-test = ["pytest (>=3.6.0,<3.9.0 || >3.9.0,<3.9.1 || >3.9.1,<3.9.2 || >3.9.2)", "pretend", "iso8601", "pytz", "hypothesis (>=1.11.4,<3.79.2 || >3.79.2)"]
+test = ["pytest (>=3.6.0,!=3.9.0,!=3.9.1,!=3.9.2)", "pretend", "iso8601", "pytz", "hypothesis (>=1.11.4,!=3.79.2)"]
 
 [[package]]
 name = "dataclasses"
@@ -466,7 +466,7 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
 parso = ">=0.7.0,<0.8.0"
 
 [package.extras]
-qa = ["flake8 (3.7.9)"]
+qa = ["flake8 (==3.7.9)"]
 testing = ["Django (<3.1)", "colorama", "docopt", "pytest (>=3.9.0,<5.0.0)"]
 
 [[package]]
@@ -496,7 +496,7 @@ SecretStorage = {version = ">=3", markers = "sys_platform == \"linux\""}
 
 [package.extras]
 docs = ["sphinx", "jaraco.packaging (>=3.2)", "rst.linker (>=1.9)"]
-testing = ["pytest (>=3.5,<3.7.3 || >3.7.3)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pytest-black (>=0.3.7)", "pytest-cov", "pytest-mypy"]
+testing = ["pytest (>=3.5,!=3.7.3)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pytest-black (>=0.3.7)", "pytest-cov", "pytest-mypy"]
 
 [[package]]
 name = "lazy-object-proxy"
@@ -803,7 +803,7 @@ py = ">=1.8.2"
 toml = "*"
 
 [package.extras]
-checkqa_mypy = ["mypy (0.780)"]
+checkqa_mypy = ["mypy (==0.780)"]
 testing = ["argcomplete", "hypothesis (>=3.56)", "mock", "nose", "requests", "xmlschema"]
 
 [[package]]
@@ -819,7 +819,7 @@ coverage = ">=4.4"
 pytest = ">=4.6"
 
 [package.extras]
-testing = ["fields", "hunter", "process-tests (2.0.2)", "six", "pytest-xdist", "virtualenv"]
+testing = ["fields", "hunter", "process-tests (==2.0.2)", "six", "pytest-xdist", "virtualenv"]
 
 [[package]]
 name = "pywin32-ctypes"
@@ -872,7 +872,7 @@ urllib3 = ">=1.21.1,<1.25.0 || >1.25.0,<1.25.1 || >1.25.1,<1.26"
 
 [package.extras]
 security = ["pyOpenSSL (>=0.14)", "cryptography (>=1.3.4)"]
-socks = ["PySocks (>=1.5.6,<1.5.7 || >1.5.7)", "win-inet-pton"]
+socks = ["PySocks (>=1.5.6,!=1.5.7)", "win-inet-pton"]
 
 [[package]]
 name = "requests-toolbelt"
@@ -1027,7 +1027,7 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, <4"
 [package.extras]
 brotli = ["brotlipy (>=0.6.0)"]
 secure = ["certifi", "cryptography (>=1.3.4)", "idna (>=2.0.0)", "pyOpenSSL (>=0.14)", "ipaddress"]
-socks = ["PySocks (>=1.5.6,<1.5.7 || >1.5.7,<2.0)"]
+socks = ["PySocks (>=1.5.6,!=1.5.7,<2.0)"]
 
 [[package]]
 name = "virtualenv"
@@ -1083,7 +1083,7 @@ python-versions = ">=3.6"
 
 [package.extras]
 docs = ["sphinx", "jaraco.packaging (>=3.2)", "rst.linker (>=1.9)"]
-testing = ["pytest (>=3.5,<3.7.3 || >3.7.3)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pytest-cov", "jaraco.test (>=3.2.0)", "jaraco.itertools", "func-timeout", "pytest-black (>=0.3.7)", "pytest-mypy"]
+testing = ["pytest (>=3.5,!=3.7.3)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pytest-cov", "jaraco.test (>=3.2.0)", "jaraco.itertools", "func-timeout", "pytest-black (>=0.3.7)", "pytest-mypy"]
 
 [metadata]
 lock-version = "1.1"
@@ -1245,28 +1245,28 @@ crashtest = [
     {file = "crashtest-0.3.1.tar.gz", hash = "sha256:42ca7b6ce88b6c7433e2ce47ea884e91ec93104a4b754998be498a8e6c3d37dd"},
 ]
 cryptography = [
-    {file = "cryptography-3.1.1-cp27-cp27m-macosx_10_10_x86_64.whl", hash = "sha256:65beb15e7f9c16e15934569d29fb4def74ea1469d8781f6b3507ab896d6d8719"},
-    {file = "cryptography-3.1.1-cp27-cp27m-manylinux1_x86_64.whl", hash = "sha256:983c0c3de4cb9fcba68fd3f45ed846eb86a2a8b8d8bc5bb18364c4d00b3c61fe"},
-    {file = "cryptography-3.1.1-cp27-cp27m-manylinux2010_x86_64.whl", hash = "sha256:e97a3b627e3cb63c415a16245d6cef2139cca18bb1183d1b9375a1c14e83f3b3"},
-    {file = "cryptography-3.1.1-cp27-cp27m-win32.whl", hash = "sha256:cb179acdd4ae1e4a5a160d80b87841b3d0e0be84af46c7bb2cd7ece57a39c4ba"},
-    {file = "cryptography-3.1.1-cp27-cp27m-win_amd64.whl", hash = "sha256:b372026ebf32fe2523159f27d9f0e9f485092e43b00a5adacf732192a70ba118"},
-    {file = "cryptography-3.1.1-cp27-cp27mu-manylinux1_x86_64.whl", hash = "sha256:680da076cad81cdf5ffcac50c477b6790be81768d30f9da9e01960c4b18a66db"},
-    {file = "cryptography-3.1.1-cp27-cp27mu-manylinux2010_x86_64.whl", hash = "sha256:5d52c72449bb02dd45a773a203196e6d4fae34e158769c896012401f33064396"},
-    {file = "cryptography-3.1.1-cp35-abi3-macosx_10_10_x86_64.whl", hash = "sha256:f0e099fc4cc697450c3dd4031791559692dd941a95254cb9aeded66a7aa8b9bc"},
-    {file = "cryptography-3.1.1-cp35-abi3-manylinux1_x86_64.whl", hash = "sha256:a7597ffc67987b37b12e09c029bd1dc43965f75d328076ae85721b84046e9ca7"},
-    {file = "cryptography-3.1.1-cp35-abi3-manylinux2010_x86_64.whl", hash = "sha256:4549b137d8cbe3c2eadfa56c0c858b78acbeff956bd461e40000b2164d9167c6"},
-    {file = "cryptography-3.1.1-cp35-abi3-manylinux2014_aarch64.whl", hash = "sha256:89aceb31cd5f9fc2449fe8cf3810797ca52b65f1489002d58fe190bfb265c536"},
-    {file = "cryptography-3.1.1-cp35-cp35m-win32.whl", hash = "sha256:559d622aef2a2dff98a892eef321433ba5bc55b2485220a8ca289c1ecc2bd54f"},
-    {file = "cryptography-3.1.1-cp35-cp35m-win_amd64.whl", hash = "sha256:451cdf60be4dafb6a3b78802006a020e6cd709c22d240f94f7a0696240a17154"},
-    {file = "cryptography-3.1.1-cp36-abi3-win32.whl", hash = "sha256:762bc5a0df03c51ee3f09c621e1cee64e3a079a2b5020de82f1613873d79ee70"},
-    {file = "cryptography-3.1.1-cp36-abi3-win_amd64.whl", hash = "sha256:b12e715c10a13ca1bd27fbceed9adc8c5ff640f8e1f7ea76416352de703523c8"},
-    {file = "cryptography-3.1.1-cp36-cp36m-win32.whl", hash = "sha256:21b47c59fcb1c36f1113f3709d37935368e34815ea1d7073862e92f810dc7499"},
-    {file = "cryptography-3.1.1-cp36-cp36m-win_amd64.whl", hash = "sha256:48ee615a779ffa749d7d50c291761dc921d93d7cf203dca2db663b4f193f0e49"},
-    {file = "cryptography-3.1.1-cp37-cp37m-win32.whl", hash = "sha256:b2bded09c578d19e08bd2c5bb8fed7f103e089752c9cf7ca7ca7de522326e921"},
-    {file = "cryptography-3.1.1-cp37-cp37m-win_amd64.whl", hash = "sha256:f99317a0fa2e49917689b8cf977510addcfaaab769b3f899b9c481bbd76730c2"},
-    {file = "cryptography-3.1.1-cp38-cp38-win32.whl", hash = "sha256:ab010e461bb6b444eaf7f8c813bb716be2d78ab786103f9608ffd37a4bd7d490"},
-    {file = "cryptography-3.1.1-cp38-cp38-win_amd64.whl", hash = "sha256:99d4984aabd4c7182050bca76176ce2dbc9fa9748afe583a7865c12954d714ba"},
-    {file = "cryptography-3.1.1.tar.gz", hash = "sha256:9d9fc6a16357965d282dd4ab6531013935425d0dc4950df2e0cf2a1b1ac1017d"},
+    {file = "cryptography-3.2.1-cp27-cp27m-macosx_10_10_x86_64.whl", hash = "sha256:6dc59630ecce8c1f558277ceb212c751d6730bd12c80ea96b4ac65637c4f55e7"},
+    {file = "cryptography-3.2.1-cp27-cp27m-manylinux1_x86_64.whl", hash = "sha256:75e8e6684cf0034f6bf2a97095cb95f81537b12b36a8fedf06e73050bb171c2d"},
+    {file = "cryptography-3.2.1-cp27-cp27m-manylinux2010_x86_64.whl", hash = "sha256:4e7268a0ca14536fecfdf2b00297d4e407da904718658c1ff1961c713f90fd33"},
+    {file = "cryptography-3.2.1-cp27-cp27m-win32.whl", hash = "sha256:7117319b44ed1842c617d0a452383a5a052ec6aa726dfbaffa8b94c910444297"},
+    {file = "cryptography-3.2.1-cp27-cp27m-win_amd64.whl", hash = "sha256:a733671100cd26d816eed39507e585c156e4498293a907029969234e5e634bc4"},
+    {file = "cryptography-3.2.1-cp27-cp27mu-manylinux1_x86_64.whl", hash = "sha256:a75f306a16d9f9afebfbedc41c8c2351d8e61e818ba6b4c40815e2b5740bb6b8"},
+    {file = "cryptography-3.2.1-cp27-cp27mu-manylinux2010_x86_64.whl", hash = "sha256:5849d59358547bf789ee7e0d7a9036b2d29e9a4ddf1ce5e06bb45634f995c53e"},
+    {file = "cryptography-3.2.1-cp35-abi3-macosx_10_10_x86_64.whl", hash = "sha256:bd717aa029217b8ef94a7d21632a3bb5a4e7218a4513d2521c2a2fd63011e98b"},
+    {file = "cryptography-3.2.1-cp35-abi3-manylinux1_x86_64.whl", hash = "sha256:efe15aca4f64f3a7ea0c09c87826490e50ed166ce67368a68f315ea0807a20df"},
+    {file = "cryptography-3.2.1-cp35-abi3-manylinux2010_x86_64.whl", hash = "sha256:32434673d8505b42c0de4de86da8c1620651abd24afe91ae0335597683ed1b77"},
+    {file = "cryptography-3.2.1-cp35-abi3-manylinux2014_aarch64.whl", hash = "sha256:7b8d9d8d3a9bd240f453342981f765346c87ade811519f98664519696f8e6ab7"},
+    {file = "cryptography-3.2.1-cp35-cp35m-win32.whl", hash = "sha256:d3545829ab42a66b84a9aaabf216a4dce7f16dbc76eb69be5c302ed6b8f4a29b"},
+    {file = "cryptography-3.2.1-cp35-cp35m-win_amd64.whl", hash = "sha256:a4e27ed0b2504195f855b52052eadcc9795c59909c9d84314c5408687f933fc7"},
+    {file = "cryptography-3.2.1-cp36-abi3-win32.whl", hash = "sha256:13b88a0bd044b4eae1ef40e265d006e34dbcde0c2f1e15eb9896501b2d8f6c6f"},
+    {file = "cryptography-3.2.1-cp36-abi3-win_amd64.whl", hash = "sha256:07ca431b788249af92764e3be9a488aa1d39a0bc3be313d826bbec690417e538"},
+    {file = "cryptography-3.2.1-cp36-cp36m-win32.whl", hash = "sha256:a035a10686532b0587d58a606004aa20ad895c60c4d029afa245802347fab57b"},
+    {file = "cryptography-3.2.1-cp36-cp36m-win_amd64.whl", hash = "sha256:d26a2557d8f9122f9bf445fc7034242f4375bd4e95ecda007667540270965b13"},
+    {file = "cryptography-3.2.1-cp37-cp37m-win32.whl", hash = "sha256:545a8550782dda68f8cdc75a6e3bf252017aa8f75f19f5a9ca940772fc0cb56e"},
+    {file = "cryptography-3.2.1-cp37-cp37m-win_amd64.whl", hash = "sha256:55d0b896631412b6f0c7de56e12eb3e261ac347fbaa5d5e705291a9016e5f8cb"},
+    {file = "cryptography-3.2.1-cp38-cp38-win32.whl", hash = "sha256:3cd75a683b15576cfc822c7c5742b3276e50b21a06672dc3a800a2d5da4ecd1b"},
+    {file = "cryptography-3.2.1-cp38-cp38-win_amd64.whl", hash = "sha256:d25cecbac20713a7c3bc544372d42d8eafa89799f492a43b79e1dfd650484851"},
+    {file = "cryptography-3.2.1.tar.gz", hash = "sha256:d3d5e10be0cf2a12214ddee45c6bd203dab435e3d83b4560c03066eda600bfe3"},
 ]
 dataclasses = [
     {file = "dataclasses-0.6-py3-none-any.whl", hash = "sha256:454a69d788c7fda44efd71e259be79577822f5e3f53f029a22d08004e951dc9f"},
@@ -1613,19 +1613,28 @@ typed-ast = [
     {file = "typed_ast-1.4.1-cp36-cp36m-macosx_10_9_x86_64.whl", hash = "sha256:269151951236b0f9a6f04015a9004084a5ab0d5f19b57de779f908621e7d8b75"},
     {file = "typed_ast-1.4.1-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:24995c843eb0ad11a4527b026b4dde3da70e1f2d8806c99b7b4a7cf491612652"},
     {file = "typed_ast-1.4.1-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:fe460b922ec15dd205595c9b5b99e2f056fd98ae8f9f56b888e7a17dc2b757e7"},
+    {file = "typed_ast-1.4.1-cp36-cp36m-manylinux2014_aarch64.whl", hash = "sha256:fcf135e17cc74dbfbc05894ebca928ffeb23d9790b3167a674921db19082401f"},
     {file = "typed_ast-1.4.1-cp36-cp36m-win32.whl", hash = "sha256:4e3e5da80ccbebfff202a67bf900d081906c358ccc3d5e3c8aea42fdfdfd51c1"},
     {file = "typed_ast-1.4.1-cp36-cp36m-win_amd64.whl", hash = "sha256:249862707802d40f7f29f6e1aad8d84b5aa9e44552d2cc17384b209f091276aa"},
     {file = "typed_ast-1.4.1-cp37-cp37m-macosx_10_9_x86_64.whl", hash = "sha256:8ce678dbaf790dbdb3eba24056d5364fb45944f33553dd5869b7580cdbb83614"},
     {file = "typed_ast-1.4.1-cp37-cp37m-manylinux1_i686.whl", hash = "sha256:c9e348e02e4d2b4a8b2eedb48210430658df6951fa484e59de33ff773fbd4b41"},
     {file = "typed_ast-1.4.1-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:bcd3b13b56ea479b3650b82cabd6b5343a625b0ced5429e4ccad28a8973f301b"},
+    {file = "typed_ast-1.4.1-cp37-cp37m-manylinux2014_aarch64.whl", hash = "sha256:f208eb7aff048f6bea9586e61af041ddf7f9ade7caed625742af423f6bae3298"},
     {file = "typed_ast-1.4.1-cp37-cp37m-win32.whl", hash = "sha256:d5d33e9e7af3b34a40dc05f498939f0ebf187f07c385fd58d591c533ad8562fe"},
     {file = "typed_ast-1.4.1-cp37-cp37m-win_amd64.whl", hash = "sha256:0666aa36131496aed8f7be0410ff974562ab7eeac11ef351def9ea6fa28f6355"},
     {file = "typed_ast-1.4.1-cp38-cp38-macosx_10_15_x86_64.whl", hash = "sha256:d205b1b46085271b4e15f670058ce182bd1199e56b317bf2ec004b6a44f911f6"},
     {file = "typed_ast-1.4.1-cp38-cp38-manylinux1_i686.whl", hash = "sha256:6daac9731f172c2a22ade6ed0c00197ee7cc1221aa84cfdf9c31defeb059a907"},
     {file = "typed_ast-1.4.1-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:498b0f36cc7054c1fead3d7fc59d2150f4d5c6c56ba7fb150c013fbc683a8d2d"},
+    {file = "typed_ast-1.4.1-cp38-cp38-manylinux2014_aarch64.whl", hash = "sha256:7e4c9d7658aaa1fc80018593abdf8598bf91325af6af5cce4ce7c73bc45ea53d"},
     {file = "typed_ast-1.4.1-cp38-cp38-win32.whl", hash = "sha256:715ff2f2df46121071622063fc7543d9b1fd19ebfc4f5c8895af64a77a8c852c"},
     {file = "typed_ast-1.4.1-cp38-cp38-win_amd64.whl", hash = "sha256:fc0fea399acb12edbf8a628ba8d2312f583bdbdb3335635db062fa98cf71fca4"},
     {file = "typed_ast-1.4.1-cp39-cp39-macosx_10_15_x86_64.whl", hash = "sha256:d43943ef777f9a1c42bf4e552ba23ac77a6351de620aa9acf64ad54933ad4d34"},
+    {file = "typed_ast-1.4.1-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:92c325624e304ebf0e025d1224b77dd4e6393f18aab8d829b5b7e04afe9b7a2c"},
+    {file = "typed_ast-1.4.1-cp39-cp39-manylinux1_i686.whl", hash = "sha256:d648b8e3bf2fe648745c8ffcee3db3ff903d0817a01a12dd6a6ea7a8f4889072"},
+    {file = "typed_ast-1.4.1-cp39-cp39-manylinux1_x86_64.whl", hash = "sha256:fac11badff8313e23717f3dada86a15389d0708275bddf766cca67a84ead3e91"},
+    {file = "typed_ast-1.4.1-cp39-cp39-manylinux2014_aarch64.whl", hash = "sha256:0d8110d78a5736e16e26213114a38ca35cb15b6515d535413b090bd50951556d"},
+    {file = "typed_ast-1.4.1-cp39-cp39-win32.whl", hash = "sha256:b52ccf7cfe4ce2a1064b18594381bccf4179c2ecf7f513134ec2f993dd4ab395"},
+    {file = "typed_ast-1.4.1-cp39-cp39-win_amd64.whl", hash = "sha256:3742b32cf1c6ef124d57f95be609c473d7ec4c14d0090e5a5e05a15269fb4d0c"},
     {file = "typed_ast-1.4.1.tar.gz", hash = "sha256:8c8aaad94455178e3187ab22c8b01a3837f8ee50e09cf31f1ba129eb293ec30b"},
 ]
 typing-extensions = [
diff --git a/pyproject.toml b/pyproject.toml
index 6c44955..a5388fa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,9 +6,12 @@ authors = ["Ethan Paul <24588726+enpaul@users.noreply.github.com>"]
 description = "Tox plugin to install Tox environment dependencies using the Poetry backend and lockfile"
 repository = "https://github.com/enpaul/tox-poetry-installer/"
 packages = [
-  {include = "tox_poetry_installer.py"},
+  {include = "tox_poetry_installer"},
   {include = "tests/*.py", format = "sdist"}
 ]
+include = [
+  "tox_poetry_installer/py.typed"
+]
 keywords = ["tox", "poetry", "plugin"]
 readme = "README.md"
 classifiers = [
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index eaa4bf1..c28e9da 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -7,7 +7,7 @@ from pathlib import Path
 
 import toml
 
-import tox_poetry_installer
+from tox_poetry_installer import __about__
 
 
 def test_metadata():
@@ -16,16 +16,14 @@ def test_metadata():
     with (Path(__file__).resolve().parent / ".." / "pyproject.toml").open() as infile:
         pyproject = toml.load(infile, _dict=dict)
 
-    assert pyproject["tool"]["poetry"]["name"] == tox_poetry_installer.__title__
-    assert pyproject["tool"]["poetry"]["version"] == tox_poetry_installer.__version__
-    assert pyproject["tool"]["poetry"]["license"] == tox_poetry_installer.__license__
-    assert (
-        pyproject["tool"]["poetry"]["description"] == tox_poetry_installer.__summary__
-    )
-    assert pyproject["tool"]["poetry"]["repository"] == tox_poetry_installer.__url__
+    assert pyproject["tool"]["poetry"]["name"] == __about__.__title__
+    assert pyproject["tool"]["poetry"]["version"] == __about__.__version__
+    assert pyproject["tool"]["poetry"]["license"] == __about__.__license__
+    assert pyproject["tool"]["poetry"]["description"] == __about__.__summary__
+    assert pyproject["tool"]["poetry"]["repository"] == __about__.__url__
     assert (
         all(
-            item in tox_poetry_installer.__authors__
+            item in __about__.__authors__
             for item in pyproject["tool"]["poetry"]["authors"]
         )
         is True
@@ -33,7 +31,7 @@ def test_metadata():
     assert (
         all(
             item in pyproject["tool"]["poetry"]["authors"]
-            for item in tox_poetry_installer.__authors__
+            for item in __about__.__authors__
         )
         is True
     )
diff --git a/tox.ini b/tox.ini
index b89285d..f262d81 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,31 +10,42 @@ deps =
     pytest-cov
     toml
 commands =
-    pytest --cov tox_poetry_installer --cov-config {toxinidir}/.coveragerc tests/ --cov-report term-missing
+    pytest --cov {envsitepackagesdir}/tox_poetry_installer --cov-config {toxinidir}/.coveragerc --cov-report term-missing tests/
 
 [testenv:static]
 description = Static formatting and quality enforcement
-require_locked_deps = true
 basepython = python3.8
+platform = linux
 ignore_errors = true
+require_locked_deps = true
 deps =
     pylint
     mypy
     black
     reorder-python-imports
     pre-commit
+allowlist_externals =
+    bash
 commands =
-    black {toxinidir}/tox_poetry_installer.py
-    reorder-python-imports {toxinidir}/tox_poetry_installer.py
+    black {toxinidir}/tox_poetry_installer/
+    # Oh man this is a doozy. If submodules are ever added to this plugin this will break, but I'm
+    # frustrated enough at this point that I'll need to take another look at it later to fix that.
+    # reorder-python-imports doesn't support handling directories on the CLI
+    # (https://github.com/asottile/reorder_python_imports/pull/76) and because the command is
+    # invoked directly (see comment below) we need file globbing to work around it.
+    # The "--unclassifiable-application-module" is a work around for reorder-python-imports not
+    # properly detecting the top-level module when run in a bash-wrapped command like this.
+    bash -c "reorder-python-imports {toxinidir}/tox_poetry_installer/*.py --unclassifiable-application-module tox_poetry_installer"
     pre-commit run --all-files
-    pylint --rcfile {toxinidir}/.pylintrc {toxinidir}/tox_poetry_installer.py
-    mypy --ignore-missing-imports --no-strict-optional {toxinidir}/tox_poetry_installer.py
+    pylint --rcfile {toxinidir}/.pylintrc {toxinidir}/tox_poetry_installer/
+    mypy --ignore-missing-imports --no-strict-optional {toxinidir}/tox_poetry_installer/
 
 [testenv:static-tests]
 description = Static formatting and quality enforcement for the tests
-require_locked_deps = true
 basepython = python3.8
+platform = linux
 ingore_errors = true
+require_locked_deps = true
 deps =
     pylint
     mypy
@@ -44,23 +55,26 @@ allowlist_externals =
     bash
 commands =
     black {toxinidir}/tests/
+    # These bash-wrapped commands hurt my face, but these tools expect directories to be valid
+    # python modules, which the "tests/" directory is not. Since tox calls all commands directly
+    # (which is good) file globbing doesn't work. To make file globbing work they need to be wrapped
+    # in a bash call (which is bad).
     bash -c "reorder-python-imports {toxinidir}/tests/*.py --unclassifiable-application-module tox_poetry_installer"
     bash -c "pylint --rcfile {toxinidir}/.pylintrc {toxinidir}/tests/*.py"
     bash -c "mypy --ignore-missing-imports --no-strict-optional {toxinidir}/tests/*.py"
 
 [testenv:security]
 description = Security checks
-require_locked_deps = true
 basepython = python3.8
-ignore_errors = true
-skip_install = true
+platform = linux
+ingore_errors = true
+require_locked_deps = true
 deps =
     bandit
     safety
     poetry
-allowlist_externals =
-    bash
 commands =
-    bandit --quiet {toxinidir}/tox_poetry_installer.py
-    bash -c "bandit --quiet --skip B101 {toxinidir}/tests/*.py"
-    bash -c "poetry export --format requirements.txt --without-hashes --dev | safety check --stdin --bare"
+    bandit --recursive --quiet {toxinidir}/tox_poetry_installer/
+    bandit --recursive --quiet --skip B101 {toxinidir}/tests/
+    poetry export --format requirements.txt --output {envtmpdir}/requirements.txt --without-hashes --dev
+    safety check --bare --file {envtmpdir}/requirements.txt
diff --git a/tox_poetry_installer.py b/tox_poetry_installer.py
deleted file mode 100644
index f8b6fae..0000000
--- a/tox_poetry_installer.py
+++ /dev/null
@@ -1,401 +0,0 @@
-"""Tox plugin for installing environments using Poetry
-
-This plugin makes use of the ``tox_testenv_install_deps`` Tox plugin hook to augment the default
-installation functionality to install dependencies from the Poetry lockfile for the project. It
-does this by using ``poetry`` to read in the lockfile, identify necessary dependencies, and then
-use Poetry's ``PipInstaller`` class to install those packages into the Tox environment.
-
-Quick definition of terminology:
-
-* "project package" - the package that Tox is testing, usually the one the current project is
-  is developing; definitionally, this is the package that is built by Tox in the ``.package`` env.
-* "project package dependency" or "project dependency" - a dependency required by the project
-  package for installation; i.e. a package that would be installed when running
-  ``pip install <project package>``.
-* "environment dependency" - a dependency specified for a given testenv in the Tox configuration.
-* "locked dependency" - a package that is present in the Poetry lockfile and will be installed
-  according to the metadata in the lockfile.
-* "unlocked dependency" - a package that is either not present in the Poetry lockfile or is not
-  specified to be installed according to the metadata in the lockfile.
-* "transiety dependency" - a package not explicitly specified for installation, but required by a
-  package that is explicitly specified.
-"""
-from pathlib import Path
-from typing import Dict
-from typing import List
-from typing import NamedTuple
-from typing import Sequence
-from typing import Set
-from typing import Tuple
-
-from poetry.core.packages import Package as PoetryPackage
-from poetry.factory import Factory as PoetryFactory
-from poetry.installation.pip_installer import PipInstaller as PoetryPipInstaller
-from poetry.io.null_io import NullIO as PoetryNullIO
-from poetry.poetry import Poetry
-from poetry.puzzle.provider import Provider as PoetryProvider
-from poetry.utils.env import VirtualEnv as PoetryVirtualEnv
-from tox import hookimpl
-from tox import reporter
-from tox.action import Action as ToxAction
-from tox.config import DepConfig as ToxDepConfig
-from tox.config import Parser as ToxParser
-from tox.venv import VirtualEnv as ToxVirtualEnv
-
-
-__title__ = "tox-poetry-installer"
-__summary__ = "Tox plugin to install Tox environment dependencies using the Poetry backend and lockfile"
-__version__ = "0.4.0"
-__url__ = "https://github.com/enpaul/tox-poetry-installer/"
-__license__ = "MIT"
-__authors__ = ["Ethan Paul <24588726+enpaul@users.noreply.github.com>"]
-
-
-# Valid PEP508 version delimiters. These are used to test whether a given string (specifically a
-# dependency name) is just a package name or also includes a version identifier.
-_PEP508_VERSION_DELIMITERS: Tuple[str, ...] = ("~=", "==", "!=", ">", "<")
-
-# Prefix all reporter messages should include to indicate that they came from this module in the
-# console output.
-_REPORTER_PREFIX = f"[{__title__}]:"
-
-# Suffix that indicates an env dependency should be treated as a locked dependency and thus be
-# installed from the lockfile. Will be automatically stripped off of a dependency name during
-# sorting so that the resulting string is just the valid package name. This becomes optional when
-# the "require_locked_deps" option is true for an environment; in that case a bare dependency like
-# 'foo' is treated the same as an explicitly locked dependency like 'foo@poetry'
-_MAGIC_SUFFIX_MARKER = "@poetry"
-
-
-# Map of package names to the package object
-PackageMap = Dict[str, PoetryPackage]
-
-
-class _SortedEnvDeps(NamedTuple):
-    unlocked_deps: List[ToxDepConfig]
-    locked_deps: List[ToxDepConfig]
-
-
-class ToxPoetryInstallerException(Exception):
-    """Error while installing locked dependencies to the test environment"""
-
-
-class LockedDepVersionConflictError(ToxPoetryInstallerException):
-    """Locked dependencies cannot specify an alternate version for installation"""
-
-
-class LockedDepNotFoundError(ToxPoetryInstallerException):
-    """Locked dependency was not found in the lockfile"""
-
-
-class ExtraNotFoundError(ToxPoetryInstallerException):
-    """Project package extra not defined in project's pyproject.toml"""
-
-
-def _sort_env_deps(venv: ToxVirtualEnv) -> _SortedEnvDeps:
-    """Sorts the environment dependencies by lock status
-
-    Lock status determines whether a given environment dependency will be installed from the
-    lockfile using the Poetry backend, or whether this plugin will skip it and allow it to be
-    installed using the default pip-based backend (an unlocked dependency).
-
-    .. note:: A locked dependency must follow a required format. To avoid reinventing the wheel
-              (no pun intended) this module does not have any infrastructure for parsing PEP-508
-              version specifiers, and so requires locked dependencies to be specified with no
-              version (the installed version being taken from the lockfile). If a dependency is
-              specified as locked and its name is also a PEP-508 string then an error will be
-              raised.
-    """
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} sorting {len(venv.envconfig.deps)} env dependencies by lock requirement"
-    )
-    unlocked_deps = []
-    locked_deps = []
-
-    for dep in venv.envconfig.deps:
-        if venv.envconfig.require_locked_deps:
-            reporter.verbosity1(
-                f"{_REPORTER_PREFIX} lock required for env, treating '{dep.name}' as locked env dependency"
-            )
-            dep.name = dep.name.replace(_MAGIC_SUFFIX_MARKER, "")
-            locked_deps.append(dep)
-        else:
-            if dep.name.endswith(_MAGIC_SUFFIX_MARKER):
-                reporter.verbosity1(
-                    f"{_REPORTER_PREFIX} specification includes marker '{_MAGIC_SUFFIX_MARKER}', treating '{dep.name}' as locked env dependency"
-                )
-                dep.name = dep.name.replace(_MAGIC_SUFFIX_MARKER, "")
-                locked_deps.append(dep)
-            else:
-                reporter.verbosity1(
-                    f"{_REPORTER_PREFIX} specification does not include marker '{_MAGIC_SUFFIX_MARKER}', treating '{dep.name}' as unlocked env dependency"
-                )
-                unlocked_deps.append(dep)
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} identified {len(locked_deps)} locked env dependencies: {[item.name for item in locked_deps]}"
-    )
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} identified {len(unlocked_deps)} unlocked env dependencies: {[item.name for item in unlocked_deps]}"
-    )
-
-    return _SortedEnvDeps(locked_deps=locked_deps, unlocked_deps=unlocked_deps)
-
-
-def _install_to_venv(
-    poetry: Poetry, venv: ToxVirtualEnv, packages: Sequence[PoetryPackage]
-):
-    """Install a bunch of packages to a virtualenv
-
-    :param poetry: Poetry object the packages were sourced from
-    :param venv: Tox virtual environment to install the packages to
-    :param packages: List of packages to install to the virtual environment
-    """
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} Installing {len(packages)} packages to environment at {venv.envconfig.envdir}"
-    )
-
-    installer = PoetryPipInstaller(
-        env=PoetryVirtualEnv(path=Path(venv.envconfig.envdir)),
-        io=PoetryNullIO(),
-        pool=poetry.pool,
-    )
-
-    for dependency in packages:
-        reporter.verbosity1(f"{_REPORTER_PREFIX} installing {dependency}")
-        installer.install(dependency)
-
-
-def _find_transients(packages: PackageMap, dependency_name: str) -> Set[PoetryPackage]:
-    """Using a poetry object identify all dependencies of a specific dependency
-
-    :param poetry: Populated poetry object which can be used to build a populated locked
-                   repository object.
-    :param dependency_name: Bare name (without version) of the dependency to fetch the transient
-                            dependencies of.
-    :returns: List of packages that need to be installed for the requested dependency.
-
-    .. note:: The package corresponding to the dependency named by ``dependency_name`` is included
-              in the list of returned packages.
-    """
-
-    try:
-        top_level = packages[dependency_name]
-
-        def find_deps_of_deps(name: str) -> List[PoetryPackage]:
-            if name in PoetryProvider.UNSAFE_PACKAGES:
-                reporter.warning(
-                    f"{_REPORTER_PREFIX} installing package '{name}' using Poetry is not supported; skipping installation of package '{name}'"
-                )
-                return []
-            transients = [packages[name]]
-            for dep in packages[name].requires:
-                transients += find_deps_of_deps(dep.name)
-            return transients
-
-        return set(find_deps_of_deps(top_level.name))
-
-    except KeyError:
-        if any(
-            delimiter in dependency_name for delimiter in _PEP508_VERSION_DELIMITERS
-        ):
-            raise LockedDepVersionConflictError(
-                f"Locked dependency '{dependency_name}' cannot include version specifier"
-            ) from None
-        raise LockedDepNotFoundError(
-            f"No version of locked dependency '{dependency_name}' found in the project lockfile"
-        ) from None
-
-
-def _install_env_dependencies(
-    venv: ToxVirtualEnv, poetry: Poetry, packages: PackageMap
-):
-    """Install the packages for a specified testenv
-
-    Processes the tox environment config, identifies any locked environment dependencies, pulls
-    them from the lockfile, and installs them to the virtual environment.
-
-    :param venv: Tox virtual environment to install the packages to
-    :param poetry: Poetry object the packages were sourced from
-    :param packages: Mapping of package names to the corresponding package object
-    """
-    env_deps = _sort_env_deps(venv)
-
-    dependencies: List[PoetryPackage] = []
-    for dep in env_deps.locked_deps:
-        try:
-            dependencies += _find_transients(packages, dep.name.lower())
-        except ToxPoetryInstallerException as err:
-            venv.status = "lockfile installation failed"
-            reporter.error(f"{_REPORTER_PREFIX} {err}")
-            raise err
-
-    if venv.envconfig.install_dev_deps:
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} env specifies 'install_env_deps = true', including Poetry dev dependencies"
-        )
-
-        dev_dependencies = [
-            dep
-            for dep in poetry.locker.locked_repository(True).packages
-            if dep not in poetry.locker.locked_repository(False).packages
-        ]
-
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} identified {len(dev_dependencies)} Poetry dev dependencies"
-        )
-
-        dependencies = list(set(dev_dependencies + dependencies))
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} identified {len(dependencies)} total dependencies from {len(env_deps.locked_deps)} locked env dependencies"
-    )
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} updating env config with {len(env_deps.unlocked_deps)} unlocked env dependencies for installation using the default backend"
-    )
-    venv.envconfig.deps = env_deps.unlocked_deps
-
-    reporter.verbosity0(
-        f"{_REPORTER_PREFIX} ({venv.name}) installing {len(dependencies)} env dependencies from lockfile"
-    )
-    _install_to_venv(poetry, venv, dependencies)
-
-
-def _install_project_dependencies(
-    venv: ToxVirtualEnv, poetry: Poetry, packages: PackageMap
-):
-    """Install the dependencies of the project package
-
-    Install all primary dependencies of the project package.
-
-    :param venv: Tox virtual environment to install the packages to
-    :param poetry: Poetry object the packages were sourced from
-    :param packages: Mapping of package names to the corresponding package object
-    """
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} performing installation of project dependencies"
-    )
-
-    base_dependencies: List[PoetryPackage] = [
-        packages[item.name]
-        for item in poetry.package.requires
-        if not item.is_optional()
-    ]
-
-    extra_dependencies: List[PoetryPackage] = []
-    for extra in venv.envconfig.extras:
-        try:
-            extra_dependencies += [
-                packages[item.name] for item in poetry.package.extras[extra]
-            ]
-        except KeyError:
-            raise ExtraNotFoundError(
-                f"Environment '{venv.name}' specifies project extra '{extra}' which was not found in the lockfile"
-            ) from None
-
-    dependencies: List[PoetryPackage] = []
-    for dep in base_dependencies + extra_dependencies:
-        try:
-            dependencies += _find_transients(packages, dep.name.lower())
-        except ToxPoetryInstallerException as err:
-            venv.status = "lockfile installation failed"
-            reporter.error(f"{_REPORTER_PREFIX} {err}")
-            raise err
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} identified {len(dependencies)} total dependencies from {len(poetry.package.requires)} project dependencies"
-    )
-
-    reporter.verbosity0(
-        f"{_REPORTER_PREFIX} ({venv.name}) installing {len(dependencies)} project dependencies from lockfile"
-    )
-    _install_to_venv(poetry, venv, dependencies)
-
-
-@hookimpl
-def tox_addoption(parser: ToxParser):
-    """Add required configuration options to the tox INI file
-
-    Adds the ``require_locked_deps`` configuration option to the venv to check whether all
-    dependencies should be treated as locked or not.
-    """
-
-    parser.add_testenv_attribute(
-        name="install_dev_deps",
-        type="bool",
-        default=False,
-        help="Automatically install all Poetry development dependencies to the environment",
-    )
-
-    parser.add_testenv_attribute(
-        name="require_locked_deps",
-        type="bool",
-        default=False,
-        help="Require all dependencies in the environment be installed using the Poetry lockfile",
-    )
-
-
-@hookimpl
-def tox_testenv_install_deps(venv: ToxVirtualEnv, action: ToxAction):
-    """Install the dependencies for the current environment
-
-    Loads the local Poetry environment and the corresponding lockfile then pulls the dependencies
-    specified by the Tox environment. Finally these dependencies are installed into the Tox
-    environment using the Poetry ``PipInstaller`` backend.
-
-    :param venv: Tox virtual environment object with configuration for the local Tox environment.
-    :param action: Tox action object
-    """
-
-    if action.name == venv.envconfig.config.isolated_build_env:
-        # Skip running the plugin for the packaging environment. PEP-517 front ends can handle
-        # that better than we can, so let them do their thing. More to the point: if you're having
-        # problems in the packaging env that this plugin would solve, god help you.
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} skipping isolated build env '{action.name}'"
-        )
-        return
-
-    try:
-        poetry = PoetryFactory().create_poetry(venv.envconfig.config.toxinidir)
-    except RuntimeError:
-        # Support running the plugin when the current tox project does not use Poetry for its
-        # environment/dependency management.
-        #
-        # ``RuntimeError`` is dangerous to blindly catch because it can be (and in Poetry's case,
-        # is) raised in many different places for different purposes.
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} project does not use Poetry for env management, skipping installation of locked dependencies"
-        )
-        return
-
-    reporter.verbosity1(
-        f"{_REPORTER_PREFIX} loaded project pyproject.toml from {poetry.file}"
-    )
-
-    package_map: PackageMap = {
-        package.name: package
-        for package in poetry.locker.locked_repository(True).packages
-    }
-
-    # Handle the installation of any locked env dependencies from the lockfile
-    _install_env_dependencies(venv, poetry, package_map)
-
-    # Handle the installation of the package dependencies from the lockfile if the package is
-    # being installed to this venv; otherwise skip installing the package dependencies
-    if venv.envconfig.skip_install:
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} env specifies 'skip_install = true', skipping installation of project package"
-        )
-        return
-
-    if venv.envconfig.config.skipsdist:
-        reporter.verbosity1(
-            f"{_REPORTER_PREFIX} config specifies 'skipsdist = true', skipping installation of project package"
-        )
-        return
-
-    _install_project_dependencies(venv, poetry, package_map)
diff --git a/tox_poetry_installer/__about__.py b/tox_poetry_installer/__about__.py
new file mode 100644
index 0000000..3211a6c
--- /dev/null
+++ b/tox_poetry_installer/__about__.py
@@ -0,0 +1,7 @@
+# pylint: disable=missing-docstring
+__title__ = "tox-poetry-installer"
+__summary__ = "Tox plugin to install Tox environment dependencies using the Poetry backend and lockfile"
+__version__ = "0.4.0"
+__url__ = "https://github.com/enpaul/tox-poetry-installer/"
+__license__ = "MIT"
+__authors__ = ["Ethan Paul <24588726+enpaul@users.noreply.github.com>"]
diff --git a/tox_poetry_installer/__init__.py b/tox_poetry_installer/__init__.py
new file mode 100644
index 0000000..7e22471
--- /dev/null
+++ b/tox_poetry_installer/__init__.py
@@ -0,0 +1,3 @@
+# pylint: disable=missing-docstring
+from tox_poetry_installer.hooks import tox_addoption
+from tox_poetry_installer.hooks import tox_testenv_install_deps
diff --git a/tox_poetry_installer/constants.py b/tox_poetry_installer/constants.py
new file mode 100644
index 0000000..a4e7933
--- /dev/null
+++ b/tox_poetry_installer/constants.py
@@ -0,0 +1,26 @@
+"""Static constants for reference
+
+Rule of thumb: if it's an arbitrary value that will never be changed at runtime, it should go
+in this module.
+
+All constants should be type hinted.
+"""
+from typing import Tuple
+
+from tox_poetry_installer import __about__
+
+
+# Valid PEP508 version delimiters. These are used to test whether a given string (specifically a
+# dependency name) is just a package name or also includes a version identifier.
+PEP508_VERSION_DELIMITERS: Tuple[str, ...] = ("~=", "==", "!=", ">", "<")
+
+# Prefix all reporter messages should include to indicate that they came from this module in the
+# console output.
+REPORTER_PREFIX = f"[{__about__.__title__}]:"
+
+# Suffix that indicates an env dependency should be treated as a locked dependency and thus be
+# installed from the lockfile. Will be automatically stripped off of a dependency name during
+# sorting so that the resulting string is just the valid package name. This becomes optional when
+# the "require_locked_deps" option is true for an environment; in that case a bare dependency like
+# 'foo' is treated the same as an explicitly locked dependency like 'foo@poetry'
+MAGIC_SUFFIX_MARKER = "@poetry"
diff --git a/tox_poetry_installer/datatypes.py b/tox_poetry_installer/datatypes.py
new file mode 100644
index 0000000..b042024
--- /dev/null
+++ b/tox_poetry_installer/datatypes.py
@@ -0,0 +1,18 @@
+"""Definitions for typehints/containers used by the plugin"""
+from typing import Dict
+from typing import List
+from typing import NamedTuple
+
+from poetry.core.packages import Package as PoetryPackage
+from tox.config import DepConfig as ToxDepConfig
+
+
+# Map of package names to the package object
+PackageMap = Dict[str, PoetryPackage]
+
+
+class SortedEnvDeps(NamedTuple):
+    """Container for the two types of environment dependencies"""
+
+    unlocked_deps: List[ToxDepConfig]
+    locked_deps: List[ToxDepConfig]
diff --git a/tox_poetry_installer/exceptions.py b/tox_poetry_installer/exceptions.py
new file mode 100644
index 0000000..969bf13
--- /dev/null
+++ b/tox_poetry_installer/exceptions.py
@@ -0,0 +1,28 @@
+"""Custom plugin exceptions
+
+All exceptions should inherit from the common base exception :exc:`ToxPoetryInstallerException`.
+
+::
+
+  ToxPoetryInstallerException
+   +-- LockedDepVersionConflictError
+   +-- LockedDepNotFoundError
+   +-- ExtraNotFoundError
+
+"""
+
+
+class ToxPoetryInstallerException(Exception):
+    """Error while installing locked dependencies to the test environment"""
+
+
+class LockedDepVersionConflictError(ToxPoetryInstallerException):
+    """Locked dependencies cannot specify an alternate version for installation"""
+
+
+class LockedDepNotFoundError(ToxPoetryInstallerException):
+    """Locked dependency was not found in the lockfile"""
+
+
+class ExtraNotFoundError(ToxPoetryInstallerException):
+    """Project package extra not defined in project's pyproject.toml"""
diff --git a/tox_poetry_installer/hooks.py b/tox_poetry_installer/hooks.py
new file mode 100644
index 0000000..d9b80c9
--- /dev/null
+++ b/tox_poetry_installer/hooks.py
@@ -0,0 +1,213 @@
+"""Main hook definition module
+
+All implementations of tox hooks are defined here, as well as any single-use helper functions
+specifically related to implementing the hooks (to keep the size/readability of the hook functions
+themselves manageable).
+"""
+from typing import List
+
+from poetry.core.packages import Package as PoetryPackage
+from poetry.factory import Factory as PoetryFactory
+from poetry.poetry import Poetry
+from tox import hookimpl
+from tox import reporter
+from tox.action import Action as ToxAction
+from tox.config import Parser as ToxParser
+from tox.venv import VirtualEnv as ToxVirtualEnv
+
+from tox_poetry_installer import constants
+from tox_poetry_installer import exceptions
+from tox_poetry_installer import utilities
+from tox_poetry_installer.datatypes import PackageMap
+
+
+@hookimpl
+def tox_addoption(parser: ToxParser):
+    """Add required configuration options to the tox INI file
+
+    Adds the ``require_locked_deps`` configuration option to the venv to check whether all
+    dependencies should be treated as locked or not.
+    """
+
+    parser.add_testenv_attribute(
+        name="install_dev_deps",
+        type="bool",
+        default=False,
+        help="Automatically install all Poetry development dependencies to the environment",
+    )
+
+    parser.add_testenv_attribute(
+        name="require_locked_deps",
+        type="bool",
+        default=False,
+        help="Require all dependencies in the environment be installed using the Poetry lockfile",
+    )
+
+
+@hookimpl
+def tox_testenv_install_deps(venv: ToxVirtualEnv, action: ToxAction):
+    """Install the dependencies for the current environment
+
+    Loads the local Poetry environment and the corresponding lockfile then pulls the dependencies
+    specified by the Tox environment. Finally these dependencies are installed into the Tox
+    environment using the Poetry ``PipInstaller`` backend.
+
+    :param venv: Tox virtual environment object with configuration for the local Tox environment.
+    :param action: Tox action object
+    """
+
+    if action.name == venv.envconfig.config.isolated_build_env:
+        # Skip running the plugin for the packaging environment. PEP-517 front ends can handle
+        # that better than we can, so let them do their thing. More to the point: if you're having
+        # problems in the packaging env that this plugin would solve, god help you.
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} skipping isolated build env '{action.name}'"
+        )
+        return
+
+    try:
+        poetry = PoetryFactory().create_poetry(venv.envconfig.config.toxinidir)
+    except RuntimeError:
+        # Support running the plugin when the current tox project does not use Poetry for its
+        # environment/dependency management.
+        #
+        # ``RuntimeError`` is dangerous to blindly catch because it can be (and in Poetry's case,
+        # is) raised in many different places for different purposes.
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} project does not use Poetry for env management, skipping installation of locked dependencies"
+        )
+        return
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} loaded project pyproject.toml from {poetry.file}"
+    )
+
+    package_map: PackageMap = {
+        package.name: package
+        for package in poetry.locker.locked_repository(True).packages
+    }
+
+    # Handle the installation of any locked env dependencies from the lockfile
+    _install_env_dependencies(venv, poetry, package_map)
+
+    # Handle the installation of the package dependencies from the lockfile if the package is
+    # being installed to this venv; otherwise skip installing the package dependencies
+    if venv.envconfig.skip_install:
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} env specifies 'skip_install = true', skipping installation of project package"
+        )
+        return
+
+    if venv.envconfig.config.skipsdist:
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} config specifies 'skipsdist = true', skipping installation of project package"
+        )
+        return
+
+    _install_project_dependencies(venv, poetry, package_map)
+
+
+def _install_env_dependencies(
+    venv: ToxVirtualEnv, poetry: Poetry, packages: PackageMap
+):
+    """Install the packages for a specified testenv
+
+    Processes the tox environment config, identifies any locked environment dependencies, pulls
+    them from the lockfile, and installs them to the virtual environment.
+
+    :param venv: Tox virtual environment to install the packages to
+    :param poetry: Poetry object the packages were sourced from
+    :param packages: Mapping of package names to the corresponding package object
+    """
+    env_deps = utilities.sort_env_deps(venv)
+
+    dependencies: List[PoetryPackage] = []
+    for dep in env_deps.locked_deps:
+        try:
+            dependencies += utilities.find_transients(packages, dep.name.lower())
+        except exceptions.ToxPoetryInstallerException as err:
+            venv.status = "lockfile installation failed"
+            reporter.error(f"{constants.REPORTER_PREFIX} {err}")
+            raise err
+
+    if venv.envconfig.install_dev_deps:
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} env specifies 'install_env_deps = true', including Poetry dev dependencies"
+        )
+
+        dev_dependencies = [
+            dep
+            for dep in poetry.locker.locked_repository(True).packages
+            if dep not in poetry.locker.locked_repository(False).packages
+        ]
+
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} identified {len(dev_dependencies)} Poetry dev dependencies"
+        )
+
+        dependencies = list(set(dev_dependencies + dependencies))
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} identified {len(dependencies)} total dependencies from {len(env_deps.locked_deps)} locked env dependencies"
+    )
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} updating env config with {len(env_deps.unlocked_deps)} unlocked env dependencies for installation using the default backend"
+    )
+    venv.envconfig.deps = env_deps.unlocked_deps
+
+    reporter.verbosity0(
+        f"{constants.REPORTER_PREFIX} ({venv.name}) installing {len(dependencies)} env dependencies from lockfile"
+    )
+    utilities.install_to_venv(poetry, venv, dependencies)
+
+
+def _install_project_dependencies(
+    venv: ToxVirtualEnv, poetry: Poetry, packages: PackageMap
+):
+    """Install the dependencies of the project package
+
+    Install all primary dependencies of the project package.
+
+    :param venv: Tox virtual environment to install the packages to
+    :param poetry: Poetry object the packages were sourced from
+    :param packages: Mapping of package names to the corresponding package object
+    """
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} performing installation of project dependencies"
+    )
+
+    base_dependencies: List[PoetryPackage] = [
+        packages[item.name]
+        for item in poetry.package.requires
+        if not item.is_optional()
+    ]
+
+    extra_dependencies: List[PoetryPackage] = []
+    for extra in venv.envconfig.extras:
+        try:
+            extra_dependencies += [
+                packages[item.name] for item in poetry.package.extras[extra]
+            ]
+        except KeyError:
+            raise exceptions.ExtraNotFoundError(
+                f"Environment '{venv.name}' specifies project extra '{extra}' which was not found in the lockfile"
+            ) from None
+
+    dependencies: List[PoetryPackage] = []
+    for dep in base_dependencies + extra_dependencies:
+        try:
+            dependencies += utilities.find_transients(packages, dep.name.lower())
+        except exceptions.ToxPoetryInstallerException as err:
+            venv.status = "lockfile installation failed"
+            reporter.error(f"{constants.REPORTER_PREFIX} {err}")
+            raise err
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} identified {len(dependencies)} total dependencies from {len(poetry.package.requires)} project dependencies"
+    )
+
+    reporter.verbosity0(
+        f"{constants.REPORTER_PREFIX} ({venv.name}) installing {len(dependencies)} project dependencies from lockfile"
+    )
+    utilities.install_to_venv(poetry, venv, dependencies)
diff --git a/tox_poetry_installer/py.typed b/tox_poetry_installer/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/tox_poetry_installer/utilities.py b/tox_poetry_installer/utilities.py
new file mode 100644
index 0000000..5ce41d0
--- /dev/null
+++ b/tox_poetry_installer/utilities.py
@@ -0,0 +1,137 @@
+"""Helper utility functions, usually bridging Tox and Poetry functionality"""
+from pathlib import Path
+from typing import List
+from typing import Sequence
+from typing import Set
+
+from poetry.core.packages import Package as PoetryPackage
+from poetry.installation.pip_installer import PipInstaller as PoetryPipInstaller
+from poetry.io.null_io import NullIO as PoetryNullIO
+from poetry.poetry import Poetry
+from poetry.puzzle.provider import Provider as PoetryProvider
+from poetry.utils.env import VirtualEnv as PoetryVirtualEnv
+from tox import reporter
+from tox.venv import VirtualEnv as ToxVirtualEnv
+
+from tox_poetry_installer import constants
+from tox_poetry_installer import exceptions
+from tox_poetry_installer.datatypes import PackageMap
+from tox_poetry_installer.datatypes import SortedEnvDeps
+
+
+def sort_env_deps(venv: ToxVirtualEnv) -> SortedEnvDeps:
+    """Sorts the environment dependencies by lock status
+
+    Lock status determines whether a given environment dependency will be installed from the
+    lockfile using the Poetry backend, or whether this plugin will skip it and allow it to be
+    installed using the default pip-based backend (an unlocked dependency).
+
+    .. note:: A locked dependency must follow a required format. To avoid reinventing the wheel
+              (no pun intended) this module does not have any infrastructure for parsing PEP-508
+              version specifiers, and so requires locked dependencies to be specified with no
+              version (the installed version being taken from the lockfile). If a dependency is
+              specified as locked and its name is also a PEP-508 string then an error will be
+              raised.
+    """
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} sorting {len(venv.envconfig.deps)} env dependencies by lock requirement"
+    )
+    unlocked_deps = []
+    locked_deps = []
+
+    for dep in venv.envconfig.deps:
+        if venv.envconfig.require_locked_deps:
+            reporter.verbosity1(
+                f"{constants.REPORTER_PREFIX} lock required for env, treating '{dep.name}' as locked env dependency"
+            )
+            dep.name = dep.name.replace(constants.MAGIC_SUFFIX_MARKER, "")
+            locked_deps.append(dep)
+        else:
+            if dep.name.endswith(constants.MAGIC_SUFFIX_MARKER):
+                reporter.verbosity1(
+                    f"{constants.REPORTER_PREFIX} specification includes marker '{constants.MAGIC_SUFFIX_MARKER}', treating '{dep.name}' as locked env dependency"
+                )
+                dep.name = dep.name.replace(constants.MAGIC_SUFFIX_MARKER, "")
+                locked_deps.append(dep)
+            else:
+                reporter.verbosity1(
+                    f"{constants.REPORTER_PREFIX} specification does not include marker '{constants.MAGIC_SUFFIX_MARKER}', treating '{dep.name}' as unlocked env dependency"
+                )
+                unlocked_deps.append(dep)
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} identified {len(locked_deps)} locked env dependencies: {[item.name for item in locked_deps]}"
+    )
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} identified {len(unlocked_deps)} unlocked env dependencies: {[item.name for item in unlocked_deps]}"
+    )
+
+    return SortedEnvDeps(locked_deps=locked_deps, unlocked_deps=unlocked_deps)
+
+
+def install_to_venv(
+    poetry: Poetry, venv: ToxVirtualEnv, packages: Sequence[PoetryPackage]
+):
+    """Install a bunch of packages to a virtualenv
+
+    :param poetry: Poetry object the packages were sourced from
+    :param venv: Tox virtual environment to install the packages to
+    :param packages: List of packages to install to the virtual environment
+    """
+
+    reporter.verbosity1(
+        f"{constants.REPORTER_PREFIX} Installing {len(packages)} packages to environment at {venv.envconfig.envdir}"
+    )
+
+    installer = PoetryPipInstaller(
+        env=PoetryVirtualEnv(path=Path(venv.envconfig.envdir)),
+        io=PoetryNullIO(),
+        pool=poetry.pool,
+    )
+
+    for dependency in packages:
+        reporter.verbosity1(f"{constants.REPORTER_PREFIX} installing {dependency}")
+        installer.install(dependency)
+
+
+def find_transients(packages: PackageMap, dependency_name: str) -> Set[PoetryPackage]:
+    """Using a poetry object identify all dependencies of a specific dependency
+
+    :param poetry: Populated poetry object which can be used to build a populated locked
+                   repository object.
+    :param dependency_name: Bare name (without version) of the dependency to fetch the transient
+                            dependencies of.
+    :returns: List of packages that need to be installed for the requested dependency.
+
+    .. note:: The package corresponding to the dependency named by ``dependency_name`` is included
+              in the list of returned packages.
+    """
+
+    try:
+        top_level = packages[dependency_name]
+
+        def find_deps_of_deps(name: str) -> List[PoetryPackage]:
+            if name in PoetryProvider.UNSAFE_PACKAGES:
+                reporter.warning(
+                    f"{constants.REPORTER_PREFIX} installing package '{name}' using Poetry is not supported; skipping installation of package '{name}'"
+                )
+                return []
+            transients = [packages[name]]
+            for dep in packages[name].requires:
+                transients += find_deps_of_deps(dep.name)
+            return transients
+
+        return set(find_deps_of_deps(top_level.name))
+
+    except KeyError:
+        if any(
+            delimiter in dependency_name
+            for delimiter in constants.PEP508_VERSION_DELIMITERS
+        ):
+            raise exceptions.LockedDepVersionConflictError(
+                f"Locked dependency '{dependency_name}' cannot include version specifier"
+            ) from None
+        raise exceptions.LockedDepNotFoundError(
+            f"No version of locked dependency '{dependency_name}' found in the project lockfile"
+        ) from None