diff --git a/libcst/codemod/_cli.py b/libcst/codemod/_cli.py
index 5c1340192..67355a190 100644
--- a/libcst/codemod/_cli.py
+++ b/libcst/codemod/_cli.py
@@ -58,7 +58,6 @@ def invoke_formatter(formatter_args: Sequence[str], code: AnyStr) -> AnyStr:
             formatter_args,
             env={},
             input=code,
-            stderr=subprocess.STDOUT,
             universal_newlines=not work_with_bytes,
             encoding=None if work_with_bytes else "utf-8",
         ),