diff --git a/README.md b/README.md
index 2003f22..9743833 100644
--- a/README.md
+++ b/README.md
@@ -237,7 +237,7 @@ This project uses poetry for dependency management. To get started, clone the re
 poetry install -E dev -E test
 ```
 
-We use `black`, `isort`, and `mypy`.
+We use `ruff` and `mypy`.
 
 ## Contributing
 
diff --git a/setup.cfg b/setup.cfg
index 4365a07..2f6cef5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -59,13 +59,11 @@ commands =
 
 [testenv:format]
 allowlist_externals =
-    isort
-    black
+    ruff
 extras =
     test
 commands =
-    isort chatlab
-    black chatlab tests
+    ruff chatlab tests
 
 [testenv:lint]
 allowlist_externals =