diff --git a/requirements_dev.txt b/requirements_dev.txt
index 7282576..4e3a6fc 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,7 +1,7 @@
 -r requirements.txt
 black==22.3.0
 flake8==4.0.1
-mypy==0.942
+mypy==0.991
 pydocstyle==6.1.1
 pylint==2.13.7
 pre-commit==2.18.1