diff --git a/pyproject.toml b/pyproject.toml
index ce6429b..18543a2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,7 +38,7 @@ source = "vcs"
 packages = ["kostky"]
 
 [tool.mypy]
-python_version = "3.9"
+python_version = "3.10"
 strict = true
 files = ["kostky"]