diff --git a/tests/test_black.py b/tests/test_black.py
index b5bfcfd0..d09b2514 100644
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -9,7 +9,5 @@ code_root = Path(__file__).parent.parent
 
 def test_black():
     runner = CliRunner()
-    result = runner.invoke(
-        black.main, [str(code_root / "tests"), str(code_root / "datasette"), "--check"]
-    )
+    result = runner.invoke(black.main, [str(code_root), "--check"])
     assert result.exit_code == 0, result.output