diff --git a/gprMax/user_objects/cmds_geometry/add_grass.py b/gprMax/user_objects/cmds_geometry/add_grass.py
index 236e593d..f6d9e098 100644
--- a/gprMax/user_objects/cmds_geometry/add_grass.py
+++ b/gprMax/user_objects/cmds_geometry/add_grass.py
@@ -23,7 +23,7 @@ import numpy as np
 from gprMax.fractals import FractalSurface, Grass
 from gprMax.grid.fdtd_grid import FDTDGrid
 from gprMax.materials import create_grass
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 from gprMax.utilities.utilities import round_value
 
@@ -32,7 +32,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class AddGrass(GeometryUserObject, Rotatable):
+class AddGrass(RotatableMixin, GeometryUserObject):
     """Adds grass with roots to a FractalBox class in the model.
 
     Attributes:
diff --git a/gprMax/user_objects/cmds_geometry/add_surface_roughness.py b/gprMax/user_objects/cmds_geometry/add_surface_roughness.py
index 248e2d43..2e49ab4f 100644
--- a/gprMax/user_objects/cmds_geometry/add_surface_roughness.py
+++ b/gprMax/user_objects/cmds_geometry/add_surface_roughness.py
@@ -22,7 +22,7 @@ import numpy as np
 
 from gprMax.fractals import FractalSurface
 from gprMax.grid.fdtd_grid import FDTDGrid
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 from gprMax.utilities.utilities import round_value
 
@@ -31,7 +31,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class AddSurfaceRoughness(GeometryUserObject, Rotatable):
+class AddSurfaceRoughness(RotatableMixin, GeometryUserObject):
     """Adds surface roughness to a FractalBox class in the model.
 
     Attributes:
diff --git a/gprMax/user_objects/cmds_geometry/add_surface_water.py b/gprMax/user_objects/cmds_geometry/add_surface_water.py
index 2a645da9..3f335d7d 100644
--- a/gprMax/user_objects/cmds_geometry/add_surface_water.py
+++ b/gprMax/user_objects/cmds_geometry/add_surface_water.py
@@ -22,7 +22,7 @@ import numpy as np
 
 from gprMax.grid.fdtd_grid import FDTDGrid
 from gprMax.materials import create_water
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 from gprMax.utilities.utilities import round_value
 
@@ -31,7 +31,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class AddSurfaceWater(GeometryUserObject, Rotatable):
+class AddSurfaceWater(RotatableMixin, GeometryUserObject):
     """Adds surface water to a FractalBox class in the model.
 
     Attributes:
diff --git a/gprMax/user_objects/cmds_geometry/box.py b/gprMax/user_objects/cmds_geometry/box.py
index 718c59c6..6b79e759 100644
--- a/gprMax/user_objects/cmds_geometry/box.py
+++ b/gprMax/user_objects/cmds_geometry/box.py
@@ -24,7 +24,7 @@ import gprMax.config as config
 from gprMax.cython.geometry_primitives import build_box
 from gprMax.grid.fdtd_grid import FDTDGrid
 from gprMax.materials import Material
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 
 from .cmds_geometry import rotate_2point_object
@@ -32,7 +32,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class Box(GeometryUserObject, Rotatable):
+class Box(RotatableMixin, GeometryUserObject):
     """Introduces an orthogonal parallelepiped with specific properties into
         the model.
 
diff --git a/gprMax/user_objects/cmds_geometry/edge.py b/gprMax/user_objects/cmds_geometry/edge.py
index 7289b242..f1fb5398 100644
--- a/gprMax/user_objects/cmds_geometry/edge.py
+++ b/gprMax/user_objects/cmds_geometry/edge.py
@@ -22,7 +22,7 @@ import numpy as np
 
 from gprMax.cython.geometry_primitives import build_edge_x, build_edge_y, build_edge_z
 from gprMax.grid.fdtd_grid import FDTDGrid
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 
 from .cmds_geometry import rotate_2point_object
@@ -30,7 +30,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class Edge(GeometryUserObject, Rotatable):
+class Edge(RotatableMixin, GeometryUserObject):
     """Introduces a wire with specific properties into the model.
 
     Attributes:
diff --git a/gprMax/user_objects/cmds_geometry/fractal_box.py b/gprMax/user_objects/cmds_geometry/fractal_box.py
index 4181e227..b6837bd1 100644
--- a/gprMax/user_objects/cmds_geometry/fractal_box.py
+++ b/gprMax/user_objects/cmds_geometry/fractal_box.py
@@ -26,13 +26,13 @@ from gprMax.fractals import FractalVolume
 from gprMax.grid.fdtd_grid import FDTDGrid
 from gprMax.materials import ListMaterial
 from gprMax.user_objects.cmds_geometry.cmds_geometry import rotate_2point_object
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 
 logger = logging.getLogger(__name__)
 
 
-class FractalBox(GeometryUserObject, Rotatable):
+class FractalBox(RotatableMixin, GeometryUserObject):
     """Introduces an orthogonal parallelepiped with fractal distributed
         properties which are related to a mixing model or normal material into
         the model.
diff --git a/gprMax/user_objects/cmds_geometry/plate.py b/gprMax/user_objects/cmds_geometry/plate.py
index 0b245450..5de480e9 100644
--- a/gprMax/user_objects/cmds_geometry/plate.py
+++ b/gprMax/user_objects/cmds_geometry/plate.py
@@ -22,7 +22,7 @@ import numpy as np
 
 from gprMax.cython.geometry_primitives import build_face_xy, build_face_xz, build_face_yz
 from gprMax.grid.fdtd_grid import FDTDGrid
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 
 from .cmds_geometry import rotate_2point_object
@@ -30,7 +30,7 @@ from .cmds_geometry import rotate_2point_object
 logger = logging.getLogger(__name__)
 
 
-class Plate(GeometryUserObject, Rotatable):
+class Plate(RotatableMixin, GeometryUserObject):
     """Introduces a plate with specific properties into the model.
 
     Attributes:
diff --git a/gprMax/user_objects/cmds_geometry/triangle.py b/gprMax/user_objects/cmds_geometry/triangle.py
index 42cab100..4a752d74 100644
--- a/gprMax/user_objects/cmds_geometry/triangle.py
+++ b/gprMax/user_objects/cmds_geometry/triangle.py
@@ -23,7 +23,7 @@ import numpy as np
 from gprMax.cython.geometry_primitives import build_triangle
 from gprMax.grid.fdtd_grid import FDTDGrid
 from gprMax.materials import Material
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GeometryUserObject
 
 from .cmds_geometry import rotate_point
@@ -31,7 +31,7 @@ from .cmds_geometry import rotate_point
 logger = logging.getLogger(__name__)
 
 
-class Triangle(GeometryUserObject, Rotatable):
+class Triangle(RotatableMixin, GeometryUserObject):
     """Introduces a triangular patch or a triangular prism with specific
         properties into the model.
 
diff --git a/gprMax/user_objects/cmds_multiuse.py b/gprMax/user_objects/cmds_multiuse.py
index 74d67ce7..fc34a347 100644
--- a/gprMax/user_objects/cmds_multiuse.py
+++ b/gprMax/user_objects/cmds_multiuse.py
@@ -49,7 +49,7 @@ from gprMax.user_objects.cmds_geometry.cmds_geometry import (
     rotate_2point_object,
     rotate_polarisation,
 )
-from gprMax.user_objects.rotatable import Rotatable
+from gprMax.user_objects.rotatable import RotatableMixin
 from gprMax.user_objects.user_objects import GridUserObject
 from gprMax.utilities.utilities import round_value
 from gprMax.waveforms import Waveform as WaveformUser
@@ -291,7 +291,7 @@ class Waveform(GridUserObject):
         grid.waveforms.append(w)
 
 
-class VoltageSource(GridUserObject, Rotatable):
+class VoltageSource(RotatableMixin, GridUserObject):
     """Specifies a voltage source at an electric field location.
 
     Attributes:
@@ -435,7 +435,7 @@ class VoltageSource(GridUserObject, Rotatable):
         grid.voltagesources.append(v)
 
 
-class HertzianDipole(GridUserObject, Rotatable):
+class HertzianDipole(RotatableMixin, GridUserObject):
     """Specifies a current density term at an electric field location.
 
     The simplest excitation, often referred to as an additive or soft source.
@@ -582,7 +582,7 @@ class HertzianDipole(GridUserObject, Rotatable):
         grid.hertziandipoles.append(h)
 
 
-class MagneticDipole(GridUserObject, Rotatable):
+class MagneticDipole(RotatableMixin, GridUserObject):
     """Simulates an infinitesimal magnetic dipole.
 
     Often referred to as an additive or soft source.
@@ -720,7 +720,7 @@ class MagneticDipole(GridUserObject, Rotatable):
         grid.magneticdipoles.append(m)
 
 
-class TransmissionLine(GridUserObject, Rotatable):
+class TransmissionLine(RotatableMixin, GridUserObject):
     """Specifies a one-dimensional transmission line model at an electric
         field location.
 
@@ -879,7 +879,7 @@ class TransmissionLine(GridUserObject, Rotatable):
         grid.transmissionlines.append(t)
 
 
-class Rx(GridUserObject, Rotatable):
+class Rx(RotatableMixin, GridUserObject):
     """Specifies output points in the model.
 
     These are locations where the values of the electric and magnetic field
diff --git a/gprMax/user_objects/rotatable.py b/gprMax/user_objects/rotatable.py
index 9f6fa2c7..19f2492d 100644
--- a/gprMax/user_objects/rotatable.py
+++ b/gprMax/user_objects/rotatable.py
@@ -4,7 +4,7 @@ from typing import Optional, Tuple
 from gprMax.grid.fdtd_grid import FDTDGrid
 
 
-class Rotatable(ABC):
+class RotatableMixin(ABC):
     """Stores parameters and defines an interface for rotatable objects.
 
     Attributes:
@@ -18,7 +18,8 @@ class Rotatable(ABC):
             otherwise. Default False.
     """
 
-    def __init__(self):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)  # Forward all unused arguments
         self.axis = "x"
         self.angle = 0
         self.origin = None