diff --git a/openfisca_core/populations/_core_population.py b/openfisca_core/populations/_core_population.py
index 8dff04137..7e160d314 100644
--- a/openfisca_core/populations/_core_population.py
+++ b/openfisca_core/populations/_core_population.py
@@ -10,8 +10,7 @@
 from openfisca_core import holders, periods
 
 from . import types as t
-from ._errors import InvalidArraySizeError
-from ._errors import PeriodValidityError
+from ._errors import InvalidArraySizeError, PeriodValidityError
 
 #: Type variable for a covariant data type.
 _DT_co = TypeVar("_DT_co", covariant=True, bound=t.VarDType)
@@ -160,7 +159,35 @@ def get_index(self, id: str) -> int:
 
     # Calculations
 
-    def check_array_compatible_with_entity(self, array: t.FloatArray) -> None:
+    def check_array_compatible_with_entity(self, array: t.VarArray) -> None:
+        """Check if an array is compatible with the population.
+
+        Args:
+            array: The array to check.
+
+        Raises:
+            InvalidArraySizeError: If the array is not compatible.
+
+        Examples:
+            >>> import numpy
+
+            >>> from openfisca_core import entities, populations
+
+            >>> class Person(entities.SingleEntity): ...
+
+            >>> person = Person("person", "people", "", "")
+            >>> population = populations.CorePopulation(person)
+            >>> population.count = 3
+
+            >>> array = numpy.array([1, 2, 3])
+            >>> population.check_array_compatible_with_entity(array)
+
+            >>> array = numpy.array([1, 2, 3, 4])
+            >>> population.check_array_compatible_with_entity(array)
+            Traceback (most recent call last):
+            InvalidArraySizeError: Input [1 2 3 4] is not a valid value for t...
+
+        """
         if self.count == array.size:
             return
         raise InvalidArraySizeError(array, self.entity.key, self.count)
diff --git a/openfisca_core/populations/_errors.py b/openfisca_core/populations/_errors.py
index 77e6c424b..b48569681 100644
--- a/openfisca_core/populations/_errors.py
+++ b/openfisca_core/populations/_errors.py
@@ -4,7 +4,7 @@
 class InvalidArraySizeError(ValueError):
     """Raised when an array has an invalid size."""
 
-    def __init__(self, array: t.FloatArray, entity: t.EntityKey, count: int) -> None:
+    def __init__(self, array: t.VarArray, entity: t.EntityKey, count: int) -> None:
         msg = (
             f"Input {array} is not a valid value for the entity {entity} "
             f"(size = {array.size} != {count} = count)."
diff --git a/openfisca_core/populations/types.py b/openfisca_core/populations/types.py
index 0cfccef36..9b90c43ef 100644
--- a/openfisca_core/populations/types.py
+++ b/openfisca_core/populations/types.py
@@ -47,6 +47,9 @@
 #: Type alias for an array of floats.
 FloatArray: TypeAlias = Array[FloatDType]
 
+#: Type alias for an array of generic objects.
+VarArray: TypeAlias = Array[VarDType]
+
 # Periods
 
 #: New type for a period integer.