diff --git a/xls2ddl/xls2crud.py b/xls2ddl/xls2crud.py
index 4916108..1d7522f 100644
--- a/xls2ddl/xls2crud.py
+++ b/xls2ddl/xls2crud.py
@@ -91,8 +91,8 @@ def subtable2toolbar(desc):
 def build_crud_ui(crud_data: dict, dbdesc: dict):
 	uidir = crud_data.output_dir
 	tables = [ k for k in dbdesc.keys() ]
-	desc = dbdesc[crud_data.tblname]
-	desc.update(crud_data.params)
+	desc = dbdesc[crud_data.tblname].copy()
+	desc.update(crud_data.params.copy())
 	subtable2toolbar(desc)
 	binds = desc.binds or []
 	if desc.relation: