diff --git a/tox.ini b/tox.ini
index b014ccf..5bc8fee 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ commands_pre =
 
 [testenv:check]
 commands =
-    black --check --diff src/compress docs
+    black --diff src/compress docs
     isort -c --df src/compress docs
     flake8 src/compress  docs
     codespell src docs