diff --git a/src/py/mat3ra/made/tools/analyze.py b/src/py/mat3ra/made/tools/analyze.py
index ef78bd26..6b9ff0d0 100644
--- a/src/py/mat3ra/made/tools/analyze.py
+++ b/src/py/mat3ra/made/tools/analyze.py
@@ -4,7 +4,7 @@
 from scipy.spatial import cKDTree
 
 from ..material import Material
-from .build.passivation.enums import SurfaceTypes
+from .enums import SurfaceTypes
 from .convert import decorator_convert_material_args_kwargs_to_atoms, to_pymatgen
 from .third_party import ASEAtoms, PymatgenIStructure, PymatgenVoronoiNN
 from .utils import decorator_handle_periodic_boundary_conditions
diff --git a/src/py/mat3ra/made/tools/build/passivation/__init__.py b/src/py/mat3ra/made/tools/build/passivation/__init__.py
index 17be2ab5..b19e061d 100644
--- a/src/py/mat3ra/made/tools/build/passivation/__init__.py
+++ b/src/py/mat3ra/made/tools/build/passivation/__init__.py
@@ -2,7 +2,7 @@
 
 from mat3ra.made.material import Material
 from .configuration import PassivationConfiguration
-from .builders import PassivationBuilder, SurfacePassivationBuilder, UndercoordinationPassivationBuilder
+from .builders import SurfacePassivationBuilder, UndercoordinationPassivationBuilder
 
 
 def create_passivation(
diff --git a/src/py/mat3ra/made/tools/build/passivation/builders.py b/src/py/mat3ra/made/tools/build/passivation/builders.py
index 576efac8..134f611f 100644
--- a/src/py/mat3ra/made/tools/build/passivation/builders.py
+++ b/src/py/mat3ra/made/tools/build/passivation/builders.py
@@ -1,10 +1,10 @@
-from typing import List
+from typing import List, Optional
 
 import numpy as np
 from mat3ra.made.material import Material
 from pydantic import BaseModel
 
-from .enums import SurfaceTypes
+from ...enums import SurfaceTypes
 from ...analyze import (
     get_surface_atom_indices,
     get_undercoordinated_atom_indices,
@@ -77,7 +77,7 @@ class SurfacePassivationBuilder(PassivationBuilder):
     Detects surface atoms looking along Z axis and passivates either the top or bottom surface or both.
     """
 
-    build_parameters: SurfacePassivationBuilderParameters = SurfacePassivationBuilderParameters()
+    build_parameters: Optional[SurfacePassivationBuilderParameters] = SurfacePassivationBuilderParameters()
     _ConfigurationType = PassivationConfiguration
 
     def create_passivated_material(self, configuration: PassivationConfiguration) -> Material:
diff --git a/src/py/mat3ra/made/tools/build/passivation/configuration.py b/src/py/mat3ra/made/tools/build/passivation/configuration.py
index 10a73b88..a106f3ec 100644
--- a/src/py/mat3ra/made/tools/build/passivation/configuration.py
+++ b/src/py/mat3ra/made/tools/build/passivation/configuration.py
@@ -1,6 +1,6 @@
 from mat3ra.made.material import Material
 
-from .enums import SurfaceTypes
+from ...enums import SurfaceTypes
 from ...build import BaseConfiguration
 
 
diff --git a/src/py/mat3ra/made/tools/build/passivation/enums.py b/src/py/mat3ra/made/tools/build/passivation/enums.py
index dba18bb4..feea29ef 100644
--- a/src/py/mat3ra/made/tools/build/passivation/enums.py
+++ b/src/py/mat3ra/made/tools/build/passivation/enums.py
@@ -1,14 +1,7 @@
 # TODO: Get this from periodic table
-from enum import Enum
 
 BOND_LENGTHS_MAP = {
     ("C", "H"): 1.09,
     ("Ni", "H"): 1.09,
     ("Si", "H"): 1.48,
 }
-
-
-class SurfaceTypes(str, Enum):
-    TOP = "top"
-    BOTTOM = "bottom"
-    BOTH = "both"
diff --git a/src/py/mat3ra/made/tools/enums.py b/src/py/mat3ra/made/tools/enums.py
new file mode 100644
index 00000000..c525714e
--- /dev/null
+++ b/src/py/mat3ra/made/tools/enums.py
@@ -0,0 +1,7 @@
+from enum import Enum
+
+
+class SurfaceTypes(str, Enum):
+    TOP = "top"
+    BOTTOM = "bottom"
+    BOTH = "both"