diff --git a/saqc/__main__.py b/saqc/__main__.py
index 4922c039230359f6bb40d859bbb98cac8f988a95..d5da0036369e3b1561e06b2cd38df59e4e5f9071 100644
--- a/saqc/__main__.py
+++ b/saqc/__main__.py
@@ -161,7 +161,7 @@ def main(
             writer,
             out.to_pandas(
                 fill_value=-9999 if scheme == "positional" else np.nan,
-                squeeze_columns=False,
+                multiindex=True,
             ),
             outfile,
         )