diff --git a/src/tcutility/molecule.py b/src/tcutility/molecule.py
index 4095f28d..0c073cb3 100644
--- a/src/tcutility/molecule.py
+++ b/src/tcutility/molecule.py
@@ -39,7 +39,7 @@ def save(mol: plams.Molecule, path: str, comment: str = None):
     """Save a molecule in a custom xyz file format.
     Molecule and atom flags can be provided as the "flags" parameter of the object (mol.flags and atom.flags).
     """
-    comment = comment or mol.comment
+    comment = comment or mol.comment if hasattr(mol, 'comment') else ''
     with open(path, "w+") as f:
         f.write(f"{len(mol.atoms)}\n{comment}\n")
         for atom in mol.atoms: