diff --git a/tests/test_physical_properties.py b/tests/test_physical_properties.py
index d66c924e..d17650fe 100644
--- a/tests/test_physical_properties.py
+++ b/tests/test_physical_properties.py
@@ -18,6 +18,7 @@
 
 import numpy as np
 import pytest
+from typing import Union, Optional
 
 from nomad.units import ureg
 from nomad.datamodel import EntryArchive
@@ -26,7 +27,10 @@
 from . import logger
 
 from nomad_simulations.variables import Variables
-from nomad_simulations.physical_property import PhysicalProperty
+from nomad_simulations.physical_property import (
+    PhysicalProperty,
+    validate_quantity_wrt_value,
+)
 
 
 class DummyPhysicalProperty(PhysicalProperty):
@@ -158,3 +162,49 @@ def test_is_derived(self):
         assert derived_physical_property._is_derived() is True
         derived_physical_property.normalize(EntryArchive(), logger)
         assert derived_physical_property.is_derived is True
+
+
+# testing `validate_quantity_wrt_value` decorator
+class ValidatingClass:
+    def __init__(self, value=None, occupation=None):
+        self.value = value
+        self.occupation = occupation
+
+    @validate_quantity_wrt_value('occupation')
+    def validate_occupation(self) -> Union[bool, np.ndarray]:
+        return self.occupation
+
+
+@pytest.mark.parametrize(
+    'value, occupation, result',
+    [
+        (None, None, False),  # Both value and occupation are None
+        (np.array([[1, 2], [3, 4]]), None, False),  # occupation is None
+        (None, np.array([[0.5, 1], [0, 0.5]]), False),  # value is None
+        (np.array([[1, 2], [3, 4]]), np.array([]), False),  # occupation is empty
+        (
+            np.array([[1, 2], [3, 4]]),
+            np.array([[0.5, 1]]),
+            False,
+        ),  # Shapes do not match
+        (
+            np.array([[1, 2], [3, 4]]),
+            np.array([[0.5, 1], [0, 0.5]]),
+            np.array([[0.5, 1], [0, 0.5]]),
+        ),  # Valid case (return `occupation`)
+    ],
+)
+def test_validate_quantity_wrt_value(
+    value: Optional[np.ndarray],
+    occupation: Optional[np.ndarray],
+    result: Union[bool, np.ndarray],
+):
+    """
+    Test the `validate_quantity_wrt_value` decorator.
+    """
+    obj = ValidatingClass(value=value, occupation=occupation)
+    validation = obj.validate_occupation()
+    if isinstance(validation, bool):
+        assert validation == result
+    else:
+        assert np.allclose(validation, result)