diff --git a/barrOs_library.py b/barrOs_library.py
index f1d8fb757f461d3f96cc245c5063f5b981db5e3f..0eb11123c4eff76f1adbe8b936f281f4af3f80f0 100644
--- a/barrOs_library.py
+++ b/barrOs_library.py
@@ -2305,7 +2305,7 @@ def run_barros(arguments, offset = 1, step = 2, local_angle_threshold = 25, dist
             if len(chains_inpdb) > 1:
                 for chainID in chains_inpdb:
                     if isfile:
-                        chain_pdb, _ = extract_chain(pdb_file, chain, outpdb = 'downloaded_pdbs/{}_{}.pdb'.format(pdbID, chainID))
+                        chain_pdb, _ = extract_chain(pdb_file, chainID, outpdb = 'downloaded_pdbs/{}_{}.pdb'.format(pdbID, chainID))
                         target_chains.append([pdbID.split('.')[0], chainID, chain_pdb, protein_type, membrane_thickness])
                     else:  
                         chain_pdb, protein_type, membrane_thickness = download_pdb('{}_{}'.format(pdbID.split('_')[0], chainID))