diff --git a/lefthook.yml b/lefthook.yml
index a26fa07..f42436c 100644
--- a/lefthook.yml
+++ b/lefthook.yml
@@ -18,6 +18,7 @@ pre-commit:
     - name: "format python"
       glob: "**/*.py"
       run: "black --quiet {staged_files}"
+      stage_fixed: true
 
     - name: "mypy"
       glob: "**/*.py"