diff --git a/tox.ini b/tox.ini
index eaa8633..a9bd6f1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,4 +20,4 @@ commands = python -m ruff check .
 
 [testenv:ruff-format]
 deps = .[lint]
-commands = python -m ruff format .
+commands = python -m ruff format --check .