diff --git a/lukefi/metsi/core/generators.py b/lukefi/metsi/core/generators.py
index 40849fe0..64b67b42 100644
--- a/lukefi/metsi/core/generators.py
+++ b/lukefi/metsi/core/generators.py
@@ -10,7 +10,7 @@
 from lukefi.metsi.core.condition import Condition
 from lukefi.metsi.core.db_utils import output_node_to_db
 from lukefi.metsi.core.exceptions import MetsiException
-from lukefi.metsi.core.model import ComputationalUnit, Finalizable
+from lukefi.metsi.core.model import ComputationalUnit
 from lukefi.metsi.core.operations import do_nothing
 from lukefi.metsi.core.simulation_payload import SimulationPayload
 from lukefi.metsi.core.treatment import Treatment
@@ -114,7 +114,7 @@ def evaluate(self,
                  node: int = 0) -> Generator[SimulationPayload[T], None, None]:
         stop = False
         for child in self.children:
-            gen = child.evaluate(payload, db, node)
+            gen = child.evaluate(copy(payload), db, node)
             for leaf in gen:
                 yield leaf
                 stop = True
@@ -257,9 +257,6 @@ def evaluate(self,
                 new_collected_data,
                 self.tags | self.treatment.default_tags)
 
-        if isinstance(new_payload.unit, Finalizable):
-            new_payload.unit.finalize()
-
         yield new_payload
 
     @override