diff --git a/ersilia/utils/identifiers/compound.py b/ersilia/utils/identifiers/compound.py
index a68db6ae6..18c98667b 100644
--- a/ersilia/utils/identifiers/compound.py
+++ b/ersilia/utils/identifiers/compound.py
@@ -182,7 +182,7 @@ async def process_smiles(self, smiles, semaphore, session, result_list):
                     logger.info("Inchikey converted using PUBCHEM")
 
             if inchikey is None:
-                inchikey = self._nci_smiles_to_inchikey(smiles)
+                inchikey = self._nci_smiles_to_inchikey(session, smiles)
                 if inchikey:
                     logger.info("Inchikey converted using NCI")