diff --git a/poetry.lock b/poetry.lock
index 7aba1d89..4c365e0f 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -90,16 +90,16 @@ immutables = ">=0.9"
 
 [[package]]
 name = "graphviz"
-version = "0.16"
+version = "0.17"
 description = "Simple Python interface for Graphviz"
 category = "main"
 optional = false
-python-versions = ">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*"
+python-versions = ">=3.6"
 
 [package.extras]
 dev = ["tox (>=3)", "flake8", "pep8-naming", "wheel", "twine"]
-docs = ["sphinx (>=1.8)", "sphinx-rtd-theme"]
-test = ["mock (>=3)", "pytest (>=4)", "pytest-mock (>=2)", "pytest-cov"]
+docs = ["sphinx (>=1.8)", "sphinx-autodoc-typehints", "sphinx-rtd-theme"]
+test = ["mock (>=3)", "pytest (>=5.2)", "pytest-mock (>=2)", "pytest-cov"]
 
 [[package]]
 name = "immutables"
@@ -328,7 +328,7 @@ testing = ["jaraco.itertools", "func-timeout"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.6"
-content-hash = "441f4ec509fbee3d303586c3abba92d71c5148600632f11c7069c709fa67774c"
+content-hash = "be417f02e076f23abb59ee7b18e6d7c170f6b560c5d6bfbfec47178c298a7c70"
 
 [metadata.files]
 appdirs = [
@@ -363,8 +363,8 @@ contextvars = [
     {file = "contextvars-2.4.tar.gz", hash = "sha256:f38c908aaa59c14335eeea12abea5f443646216c4e29380d7bf34d2018e2c39e"},
 ]
 graphviz = [
-    {file = "graphviz-0.16-py2.py3-none-any.whl", hash = "sha256:3cad5517c961090dfc679df6402a57de62d97703e2880a1a46147bb0dc1639eb"},
-    {file = "graphviz-0.16.zip", hash = "sha256:d2d25af1c199cad567ce4806f0449cb74eb30cf451fd7597251e1da099ac6e57"},
+    {file = "graphviz-0.17-py3-none-any.whl", hash = "sha256:5dadec94046d82adaae6019311a30e0487536d9d5a60d85451f0ba32f9fc6559"},
+    {file = "graphviz-0.17.zip", hash = "sha256:ef6e2c5deb9cdcc0c7eece1d89625fd07b0f2208ea2bcb483520907ddf8b4e12"},
 ]
 immutables = [
     {file = "immutables-0.11-cp35-cp35m-macosx_10_13_x86_64.whl", hash = "sha256:bce27277a2fe91509cca69181971ab509c2ee862e8b37b09f26b64f90e8fe8fb"},
diff --git a/pyproject.toml b/pyproject.toml
index 7d126d54..3dcaeed3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ include = ["resources/**/*"]
 
 [tool.poetry.dependencies]
 python = "^3.6"
-graphviz = ">=0.13.2,<0.17.0"
+graphviz = ">=0.13.2,<0.18.0"
 jinja2 = "^2.10"
 contextvars = { version = "^2.4", python = "~3.6" }