diff --git a/modules/mol/alg/src/biounit.cc b/modules/mol/alg/src/biounit.cc
index e5fd1644f680b884c84cfb582a19ff05f52b576d..72e2cc97034f2fa48a78e980797bc78e3bc51aa2 100644
--- a/modules/mol/alg/src/biounit.cc
+++ b/modules/mol/alg/src/biounit.cc
@@ -344,7 +344,8 @@ ost::mol::EntityHandle CreateBU(const ost::mol::EntityHandle& asu,
       // connect
       for(auto it = bond_list.begin(); it != bond_list.end(); ++it) {
         ed.Connect(atom_mapper[it->GetFirst().GetHashCode()],
-                   atom_mapper[it->GetSecond().GetHashCode()]);
+                   atom_mapper[it->GetSecond().GetHashCode()],
+                   it->GetBondOrder());
       }
 
     }