diff --git a/overrides/build-systems.json b/overrides/build-systems.json
index ea3cfcb..fcbe1ef 100644
--- a/overrides/build-systems.json
+++ b/overrides/build-systems.json
@@ -2,6 +2,12 @@
   "HTSeq": [
     "cython"
   ],
+  "sentinel": [
+    "poetry-core"
+  ],
+  "strawberry-graphql": [
+    "poetry"
+  ],
   "PyStemmer": [
     "cython"
   ],
diff --git a/tests/default.nix b/tests/default.nix
index 7836742..462daf5 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -56,6 +56,7 @@ builtins.removeAttrs
   source-filter = callTest ./source-filter { };
   canonical-module-names = callTest ./canonical-module-names { };
   wandb = callTest ./wandb { };
+  utf8-pyproject = callTest ./utf8-pyproject { };
 
   # Test deadlocks on darwin, sandboxing issue?
   dependency-environment = skipOSX (callTest ./dependency-environment { });
diff --git a/tests/utf8-pyproject/default.nix b/tests/utf8-pyproject/default.nix
new file mode 100644
index 0000000..a0797b4
--- /dev/null
+++ b/tests/utf8-pyproject/default.nix
@@ -0,0 +1,6 @@
+{ lib, poetry2nix, python3 }:
+
+poetry2nix.mkPoetryApplication {
+  python = python3;
+  projectDir = ./.;
+}
diff --git a/tests/utf8-pyproject/poetry.lock b/tests/utf8-pyproject/poetry.lock
new file mode 100644
index 0000000..6d85453
--- /dev/null
+++ b/tests/utf8-pyproject/poetry.lock
@@ -0,0 +1,171 @@
+[[package]]
+name = "backports.cached-property"
+version = "1.0.1"
+description = "cached_property() - computed once per instance, cached as attribute"
+category = "main"
+optional = false
+python-versions = ">=3.6.0"
+
+[[package]]
+name = "click"
+version = "8.0.3"
+description = "Composable command line interface toolkit"
+category = "main"
+optional = false
+python-versions = ">=3.6"
+
+[package.dependencies]
+colorama = {version = "*", markers = "platform_system == \"Windows\""}
+
+[[package]]
+name = "colorama"
+version = "0.4.4"
+description = "Cross-platform colored terminal text."
+category = "main"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
+
+[[package]]
+name = "graphql-core"
+version = "3.1.7"
+description = "GraphQL implementation for Python, a port of GraphQL.js, the JavaScript reference implementation for GraphQL."
+category = "main"
+optional = false
+python-versions = ">=3.6,<4"
+
+[[package]]
+name = "pygments"
+version = "2.11.2"
+description = "Pygments is a syntax highlighting package written in Python."
+category = "main"
+optional = false
+python-versions = ">=3.5"
+
+[[package]]
+name = "python-dateutil"
+version = "2.8.2"
+description = "Extensions to the standard Python datetime module"
+category = "main"
+optional = false
+python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,>=2.7"
+
+[package.dependencies]
+six = ">=1.5"
+
+[[package]]
+name = "python-multipart"
+version = "0.0.5"
+description = "A streaming multipart parser for Python"
+category = "main"
+optional = false
+python-versions = "*"
+
+[package.dependencies]
+six = ">=1.4.0"
+
+[[package]]
+name = "sentinel"
+version = "0.3.0"
+description = "Create sentinel objects, akin to None, NotImplemented, Ellipsis"
+category = "main"
+optional = false
+python-versions = ">=3.6,<4.0"
+
+[package.extras]
+varname = ["varname (>=0.1)"]
+
+[[package]]
+name = "six"
+version = "1.16.0"
+description = "Python 2 and 3 compatibility utilities"
+category = "main"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*"
+
+[[package]]
+name = "strawberry-graphql"
+version = "0.95.3"
+description = "A library for creating GraphQL APIs"
+category = "main"
+optional = false
+python-versions = ">=3.7,<4.0"
+
+[package.dependencies]
+"backports.cached-property" = ">=1.0.1,<2.0.0"
+click = ">=7.0,<9.0"
+graphql-core = ">=3.1.0,<3.2.0"
+pygments = ">=2.3,<3.0"
+python-dateutil = ">=2.7.0,<3.0.0"
+python-multipart = ">=0.0.5,<0.0.6"
+sentinel = ">=0.3.0,<0.4.0"
+typing_extensions = ">=3.7.4,<5.0.0"
+
+[package.extras]
+asgi = ["starlette (>=0.13.6,<0.17.0)"]
+debug-server = ["starlette (>=0.13.6,<0.17.0)", "uvicorn (>=0.11.6,<0.17.0)"]
+django = ["Django (>=2.2,<4)", "Django (>=2.2,<5)", "asgiref (>=3.2,<4.0)"]
+flask = ["flask (>=1.1,<2.0)"]
+opentelemetry = ["opentelemetry-api (<2)", "opentelemetry-sdk (<2)"]
+chalice = ["chalice (>=1.22,<2.0)"]
+pydantic = ["pydantic (<2)"]
+sanic = ["sanic (>=20.12.2,<22.0.0)"]
+aiohttp = ["aiohttp (>=3.7.4.post0,<4.0.0)"]
+fastapi = ["fastapi (>=0.65.2)"]
+
+[[package]]
+name = "typing-extensions"
+version = "4.0.1"
+description = "Backported and Experimental Type Hints for Python 3.6+"
+category = "main"
+optional = false
+python-versions = ">=3.6"
+
+[metadata]
+lock-version = "1.1"
+python-versions = "^3.9"
+content-hash = "8cfb2298aef26dee0a9f3c9bca1bd7c6e963f7aefeddcd317c56ccef3cfdcb3d"
+
+[metadata.files]
+"backports.cached-property" = [
+    {file = "backports.cached-property-1.0.1.tar.gz", hash = "sha256:1a5ef1e750f8bc7d0204c807aae8e0f450c655be0cf4b30407a35fd4bb27186c"},
+    {file = "backports.cached_property-1.0.1-py3-none-any.whl", hash = "sha256:687b5fe14be40aadcf547cae91337a1fdb84026046a39370274e54d3fe4fb4f9"},
+]
+click = [
+    {file = "click-8.0.3-py3-none-any.whl", hash = "sha256:353f466495adaeb40b6b5f592f9f91cb22372351c84caeb068132442a4518ef3"},
+    {file = "click-8.0.3.tar.gz", hash = "sha256:410e932b050f5eed773c4cda94de75971c89cdb3155a72a0831139a79e5ecb5b"},
+]
+colorama = [
+    {file = "colorama-0.4.4-py2.py3-none-any.whl", hash = "sha256:9f47eda37229f68eee03b24b9748937c7dc3868f906e8ba69fbcbdd3bc5dc3e2"},
+    {file = "colorama-0.4.4.tar.gz", hash = "sha256:5941b2b48a20143d2267e95b1c2a7603ce057ee39fd88e7329b0c292aa16869b"},
+]
+graphql-core = [
+    {file = "graphql-core-3.1.7.tar.gz", hash = "sha256:62ec192150ccecd9a18cfb79e3e72eb7d1fd68fb594ef19c40099b6deec8ef0c"},
+    {file = "graphql_core-3.1.7-py3-none-any.whl", hash = "sha256:9b460f60320be01c7f3b1766cf3e406933003008055079b9d983b8f3988f4400"},
+]
+pygments = [
+    {file = "Pygments-2.11.2-py3-none-any.whl", hash = "sha256:44238f1b60a76d78fc8ca0528ee429702aae011c265fe6a8dd8b63049ae41c65"},
+    {file = "Pygments-2.11.2.tar.gz", hash = "sha256:4e426f72023d88d03b2fa258de560726ce890ff3b630f88c21cbb8b2503b8c6a"},
+]
+python-dateutil = [
+    {file = "python-dateutil-2.8.2.tar.gz", hash = "sha256:0123cacc1627ae19ddf3c27a5de5bd67ee4586fbdd6440d9748f8abb483d3e86"},
+    {file = "python_dateutil-2.8.2-py2.py3-none-any.whl", hash = "sha256:961d03dc3453ebbc59dbdea9e4e11c5651520a876d0f4db161e8674aae935da9"},
+]
+python-multipart = [
+    {file = "python-multipart-0.0.5.tar.gz", hash = "sha256:f7bb5f611fc600d15fa47b3974c8aa16e93724513b49b5f95c81e6624c83fa43"},
+]
+sentinel = [
+    {file = "sentinel-0.3.0-py3-none-any.whl", hash = "sha256:bd8710dd26752039c668604f6be2aaf741b56f7811c5924a4dcdfd74359244f3"},
+    {file = "sentinel-0.3.0.tar.gz", hash = "sha256:f28143aa4716dbc8f6193f5682176a3c33cd26aaae05d9ecf66c186a9887cc2d"},
+]
+six = [
+    {file = "six-1.16.0-py2.py3-none-any.whl", hash = "sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254"},
+    {file = "six-1.16.0.tar.gz", hash = "sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926"},
+]
+strawberry-graphql = [
+    {file = "strawberry-graphql-0.95.3.tar.gz", hash = "sha256:5e1882af281ff9cfd0d4a4fcafe3671411049ce14d13a09fa32a204ac575267c"},
+    {file = "strawberry_graphql-0.95.3-py3-none-any.whl", hash = "sha256:60709c41df30f1403f97dba22218711fb5e174b34f3a967062c2ccd6ef79360a"},
+]
+typing-extensions = [
+    {file = "typing_extensions-4.0.1-py3-none-any.whl", hash = "sha256:7f001e5ac290a0c0401508864c7ec868be4e701886d5b573a9528ed3973d9d3b"},
+    {file = "typing_extensions-4.0.1.tar.gz", hash = "sha256:4ca091dea149f945ec56afb48dae714f21e8692ef22a395223bcd328961b6a0e"},
+]
diff --git a/tests/utf8-pyproject/pyproject.toml b/tests/utf8-pyproject/pyproject.toml
new file mode 100644
index 0000000..287cd38
--- /dev/null
+++ b/tests/utf8-pyproject/pyproject.toml
@@ -0,0 +1,15 @@
+[tool.poetry]
+name = "utf8-pyproject"
+version = "0.1.0"
+description = ""
+authors = ["Your Name <you@example.com>"]
+
+[tool.poetry.dependencies]
+python = "^3.9"
+strawberry-graphql = "^0.95.3"
+
+[tool.poetry.dev-dependencies]
+
+[build-system]
+requires = ["poetry-core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"
diff --git a/tests/utf8-pyproject/utf8_pyproject/__init__.py b/tests/utf8-pyproject/utf8_pyproject/__init__.py
new file mode 100644
index 0000000..e69de29