diff --git a/mmtbx/monomer_library/pdb_interpretation.py b/mmtbx/monomer_library/pdb_interpretation.py
index dfbb1b6411..73859d1445 100644
--- a/mmtbx/monomer_library/pdb_interpretation.py
+++ b/mmtbx/monomer_library/pdb_interpretation.py
@@ -2664,7 +2664,8 @@ def __init__(self,
     #
     # Deep copy is needed in case of altlocs
     #
-    apply_restraints_specifications_dc = deepcopy(apply_restraints_specifications)
+    #apply_restraints_specifications_dc = deepcopy(apply_restraints_specifications)
+    apply_restraints_specifications_dc = apply_restraints_specifications
     #
     for i_residue,residue in enumerate(pdb_residues):
       def _get_next_residue():