diff --git a/requirements.txt b/requirements.txt
index ca7c876..5108fdf 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -34,5 +34,5 @@ pyyaml>=6.0.0
 pytest>=8.0.0
 pytest-asyncio>=0.24.0
 
-# Code quality (provided by nix devshell, not pip)
-# ruff
+# Code quality
+ruff>=0.4.0