diff --git a/cml/shared/request.py b/cml/shared/request.py
index 31198797da125d21f5d0f81e27524734c96df0f6..fb2c5e215753e5a059ba7fe91cdc30f200a68952 100644
--- a/cml/shared/request.py
+++ b/cml/shared/request.py
@@ -1,13 +1,16 @@
 from dataclasses import dataclass
+from typing import Callable, Iterable
 
 from cml.ports.source_adapters import Adapter
+from cml.ports.scikit_adapter import MachineLearningModel
 from cml.domain.reconstruction import Reconstructor
 from cml.domain.data_source import DataSource
 from cml.domain.construction import Constructor
 from cml.shared.settings import (
     PreprocessingSettings,
     BlockProcessingSettings,
-    DeconstructionSettings
+    DeconstructionSettings,
+    ConstructionSettings
 )
 
 
@@ -16,6 +19,8 @@ class PreprocessRequest:
     source_adapter: Adapter
     pre_settings: PreprocessingSettings
     block_settings: BlockProcessingSettings
+    density_estimator: MachineLearningModel
+    relative_extrema: Callable
 
 
 @dataclass