diff --git a/package/FOC_reduction.py b/package/FOC_reduction.py
index b42f57f..dcea9fa 100755
--- a/package/FOC_reduction.py
+++ b/package/FOC_reduction.py
@@ -273,7 +273,7 @@ def main(target=None, proposal_id=None, infiles=None, output_dir="./data", crop=
         flux_data=np.array([flux_data, flux_error, flux_mask]),
         flux_head=flux_head,
     )
-    outfiles.append("/".join([data_folder, Stokes_hdul[0].header["FILENAME"] + ".fits"]))
+    outfiles.append("/".join([data_folder, Stokes_hdul["I_STOKES"].header["FILENAME"] + ".fits"]))
 
     # Step 5:
     # crop to desired region of interest (roi)