diff --git a/poetry.lock b/poetry.lock
index 94b9c19..1b8d161 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -30,7 +30,7 @@ tests_no_zope = ["coverage[toml] (>=5.0.2)", "hypothesis", "pympler", "pytest (>
 
 [[package]]
 name = "black"
-version = "21.6b0"
+version = "21.7b0"
 description = "The uncompromising code formatter."
 category = "main"
 optional = false
@@ -42,7 +42,7 @@ click = ">=7.1.2"
 mypy-extensions = ">=0.4.3"
 pathspec = ">=0.8.1,<1"
 regex = ">=2020.1.8"
-toml = ">=0.10.1"
+tomli = ">=0.2.6,<2.0.0"
 
 [package.extras]
 colorama = ["colorama (>=0.4.3)"]
@@ -245,10 +245,18 @@ category = "main"
 optional = false
 python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
 
+[[package]]
+name = "tomli"
+version = "1.0.4"
+description = "A lil' TOML parser"
+category = "main"
+optional = false
+python-versions = ">=3.6"
+
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.9"
-content-hash = "4bf7a6a3846c8ead94622dca66cdc83f3dcaae58763ce06428c11e3d4379d0b7"
+content-hash = "b3beb4788fcbfb1fe31c5ad7022e778e17cac95b513546702736827c97a28125"
 
 [metadata.files]
 appdirs = [
@@ -264,8 +272,8 @@ attrs = [
     {file = "attrs-20.3.0.tar.gz", hash = "sha256:832aa3cde19744e49938b91fea06d69ecb9e649c93ba974535d08ad92164f700"},
 ]
 black = [
-    {file = "black-21.6b0-py3-none-any.whl", hash = "sha256:dfb8c5a069012b2ab1e972e7b908f5fb42b6bbabcba0a788b86dc05067c7d9c7"},
-    {file = "black-21.6b0.tar.gz", hash = "sha256:dc132348a88d103016726fe360cb9ede02cecf99b76e3660ce6c596be132ce04"},
+    {file = "black-21.7b0-py3-none-any.whl", hash = "sha256:1c7aa6ada8ee864db745b22790a32f94b2795c253a75d6d9b5e439ff10d23116"},
+    {file = "black-21.7b0.tar.gz", hash = "sha256:c8373c6491de9362e39271630b65b964607bc5c79c83783547d76c839b3aa219"},
 ]
 click = [
     {file = "click-7.1.2-py2.py3-none-any.whl", hash = "sha256:dacca89f4bfadd5de3d7489b7c8a566eee0d3676333fbb50030263894c38c0dc"},
@@ -387,3 +395,7 @@ toml = [
     {file = "toml-0.10.2-py2.py3-none-any.whl", hash = "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b"},
     {file = "toml-0.10.2.tar.gz", hash = "sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f"},
 ]
+tomli = [
+    {file = "tomli-1.0.4-py3-none-any.whl", hash = "sha256:0713b16ff91df8638a6a694e295c8159ab35ba93e3424a626dd5226d386057be"},
+    {file = "tomli-1.0.4.tar.gz", hash = "sha256:be670d0d8d7570fd0ea0113bd7bb1ba3ac6706b4de062cc4c952769355c9c268"},
+]
diff --git a/pyproject.toml b/pyproject.toml
index e7d5203..9841ef7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ python = "^3.9"
 invoke = "1.6.0"
 pytest = "6.2.4"
 
-black = { version = "^21.6b0", allow-prereleases = true }
+black = { version = "^21.7b0", allow-prereleases = true }
 codespell = ">=2.0.0"
 flake8 = "^3.9.2"
 pep8-naming = "^0.12.0"