diff --git a/requirements-dev.txt b/requirements-dev.txt
index 64d8ee0b..02a60ed7 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -4,6 +4,10 @@ flake8>=3  # pyup: ignore
 tox==4.23.2
 # Extras
 pytimeparse==1.1.8
+# [toml] extra
+tomli>=2,<3; python_version=="3.9"
+tomli>=2,<3; python_version=="3.10"
+tomli-w>=1,<2
 # TODO I don't know if we need the below on CI
 coverage>=6.2
 pip>=21.3.1