diff --git a/modules/project_invoice/invoice.py b/modules/project_invoice/invoice.py
index 769adb99b9..0f41d31ec1 100644
--- a/modules/project_invoice/invoice.py
+++ b/modules/project_invoice/invoice.py
@@ -109,6 +109,13 @@ class InvoiceLine(metaclass=PoolMeta):
         super().validate_fields(lines, field_names)
         cls.check_validate_project_invoice_quantity(lines, field_names)
 
+    @classmethod
+    def copy(cls, lines, default=None):
+        default = default.copy() if default is not None else {}
+        default.setdefault('project_invoice_works')
+        default.setdefault('project_invoice_progresses')
+        return super().copy(lines, default=default)
+
     @classmethod
     def delete(cls, lines):
         pool = Pool()