diff --git a/pyproject.toml b/pyproject.toml
index 20e9f61..0e5e5ef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@ scipy = "1.10"
 pytest = ">=6"
 flake8 = "^4.0.1"
 pytest-cov = "^3.0.0"
-mypy = "^0.971"
+mypy = "^0.991"
 python-semantic-release = "^7.24.0"
 black = "^22.3.0"