diff --git a/actions/ost-compare-ligand-structures b/actions/ost-compare-ligand-structures
index b28384cf18ed3572ba240a72d7ecc5fd43cd5f2e..0ecaeb42161eb80a7655f3cb48c7cf6ccd11bf29 100644
--- a/actions/ost-compare-ligand-structures
+++ b/actions/ost-compare-ligand-structures
@@ -432,7 +432,11 @@ def _LoadLigand(file):
     """
     Load a single ligand from file names. Return an entity.
     """
-    return ost.io.LoadEntity(file, format="sdf")
+    ent = ost.io.LoadEntity(file, format="sdf")
+    ed = ent.EditXCS()
+    ed.RenameChain(ent.chains[0], file)
+    ed.UpdateICS()
+    return ent
 
 
 def _CleanupStructure(entity):