diff --git a/openfisca_core/indexed_enums/_enum_type.py b/openfisca_core/indexed_enums/_enum_type.py
index 8083a6d49..9b95364a2 100644
--- a/openfisca_core/indexed_enums/_enum_type.py
+++ b/openfisca_core/indexed_enums/_enum_type.py
@@ -66,5 +66,14 @@ def __new__(
     def __dir__(cls) -> list[str]:
         return sorted({"indices", "names", "enums", *super().__dir__()})
 
+    def __hash__(cls) -> int:
+        return object.__hash__(cls.__name__)
+
+    def __eq__(cls, other: object) -> bool:
+        return hash(cls) == hash(other)
+
+    def __ne__(cls, other: object) -> bool:
+        return hash(cls) != hash(other)
+
 
 __all__ = ["EnumType"]
diff --git a/openfisca_core/indexed_enums/_utils.py b/openfisca_core/indexed_enums/_utils.py
index aa676b92f..67c9e741b 100644
--- a/openfisca_core/indexed_enums/_utils.py
+++ b/openfisca_core/indexed_enums/_utils.py
@@ -92,8 +92,7 @@ def _int_to_index(
         ...     )
 
         >>> _int_to_index(Road, 1)
-        Traceback (most recent call last):
-        TypeError: 'int' object is not iterable
+        array([1], dtype=uint8)
 
         >>> _int_to_index(Road, [1])
         array([1], dtype=uint8)
@@ -105,8 +104,7 @@ def _int_to_index(
         array([1], dtype=uint8)
 
         >>> _int_to_index(Road, numpy.array(1))
-        Traceback (most recent call last):
-        TypeError: iteration over a 0-d array
+        array([1], dtype=uint8)
 
         >>> _int_to_index(Road, numpy.array([1]))
         array([1], dtype=uint8)
@@ -118,9 +116,9 @@ def _int_to_index(
         array([1, 1], dtype=uint8)
 
     """
-    return numpy.array(
-        [index for index in value if index < len(enum_class.__members__)], t.EnumDType
-    )
+    indices = enum_class.indices
+    values = numpy.array(value, copy=False)
+    return values[values < indices.size].astype(t.EnumDType)
 
 
 def _str_to_index(
@@ -155,14 +153,13 @@ def _str_to_index(
         ...     )
 
         >>> _str_to_index(Road, "AVENUE")
-        array([], dtype=uint8)
+        array([1], dtype=uint8)
 
         >>> _str_to_index(Road, ["AVENUE"])
         array([1], dtype=uint8)
 
         >>> _str_to_index(Road, numpy.array("AVENUE"))
-        Traceback (most recent call last):
-        TypeError: iteration over a 0-d array
+        array([1], dtype=uint8)
 
         >>> _str_to_index(Road, numpy.array(["AVENUE"]))
         array([1], dtype=uint8)
@@ -174,14 +171,12 @@ def _str_to_index(
         array([1, 1], dtype=uint8)
 
     """
-    return numpy.array(
-        [
-            enum_class.__members__[name].index
-            for name in value
-            if name in enum_class._member_names_
-        ],
-        t.EnumDType,
-    )
+    values = numpy.array(value, copy=False)
+    names = enum_class.names
+    mask = numpy.isin(values, names)
+    sorter = numpy.argsort(names)
+    result = sorter[numpy.searchsorted(names, values[mask], sorter=sorter)]
+    return result.astype(t.EnumDType)
 
 
 __all__ = ["_enum_to_index", "_int_to_index", "_str_to_index"]
diff --git a/openfisca_core/indexed_enums/enum.py b/openfisca_core/indexed_enums/enum.py
index a733fd5da..43a893e85 100644
--- a/openfisca_core/indexed_enums/enum.py
+++ b/openfisca_core/indexed_enums/enum.py
@@ -117,13 +117,6 @@ def __init__(self, *__args: object, **__kwargs: object) -> None:
         """
         self.index = len(self._member_names_)
 
-    # Bypass the slow Enum.__eq__
-    __eq__ = object.__eq__
-
-    # In Python 3, __hash__ must be defined if __eq__ is defined to stay
-    # hashable.
-    __hash__ = object.__hash__
-
     def __repr__(self) -> str:
         return f"{self.__class__.__name__}.{self.name}"
 
@@ -199,7 +192,7 @@ def _encode_array(cls, value: t.VarArray) -> t.EnumArray:
             indices = _int_to_index(cls, value)
         elif _is_str_array(value):  # type: ignore[unreachable]
             indices = _str_to_index(cls, value)
-        elif _is_enum_array(value) and cls.__name__ is value[0].__class__.__name__:
+        elif _is_enum_array(value) and cls == value[0].__class__:
             indices = _enum_to_index(value)
         else:
             raise EnumEncodingError(cls, value)
diff --git a/openfisca_core/indexed_enums/enum_array.py b/openfisca_core/indexed_enums/enum_array.py
index 98f9b4c6a..65bc209a7 100644
--- a/openfisca_core/indexed_enums/enum_array.py
+++ b/openfisca_core/indexed_enums/enum_array.py
@@ -153,10 +153,7 @@ def __eq__(self, other: object) -> t.BoolArray:  # type: ignore[override]
             return NotImplemented
         if other is None:
             return NotImplemented
-        if (
-            isinstance(other, type(t.Enum))
-            and other.__name__ is self.possible_values.__name__
-        ):
+        if isinstance(other, type(t.Enum)) and other == self.possible_values:
             result = (
                 self.view(numpy.ndarray)
                 == self.possible_values.indices[
@@ -164,10 +161,7 @@ def __eq__(self, other: object) -> t.BoolArray:  # type: ignore[override]
                 ]
             )
             return result
-        if (
-            isinstance(other, t.Enum)
-            and other.__class__.__name__ is self.possible_values.__name__
-        ):
+        if isinstance(other, t.Enum) and other.__class__ == self.possible_values:
             result = self.view(numpy.ndarray) == other.index
             return result
         # For NumPy >=1.26.x.