diff --git a/openfisca_core/indexed_enums.py b/openfisca_core/indexed_enums.py
index c4091aee0d..736dd8a8e8 100644
--- a/openfisca_core/indexed_enums.py
+++ b/openfisca_core/indexed_enums.py
@@ -9,8 +9,6 @@
     logical_not as not_,
     ndarray,
     select,
-    size,
-    take,
     )
 
 ENUM_ARRAY_DTYPE = int16
@@ -85,11 +83,8 @@ def encode(
             # gives them a different identity from the ones imported in the usual way.
             # So, instead of relying on the "cls" passed in, we use only its name to
             # check that the values in the array, if non-empty, are of the right type.
-            array_size: int = size(array)
-            array_name: str = take(array, 0).__class__.__name__
-
-            if array_size > 0 and array_name is cls.__name__:
-                cls = take(array, 0).__class__
+            if len(array) > 0 and array[0].__class__.__name__ is cls.__name__:
+                cls = array[0].__class__
 
             array = select(
                 [array == item for item in cls],
diff --git a/tests/core/test_indexed_enums.py b/tests/core/test_indexed_enums.py
index 6e5cde12c1..2d2347bb53 100644
--- a/tests/core/test_indexed_enums.py
+++ b/tests/core/test_indexed_enums.py
@@ -49,9 +49,8 @@ def test_enum_encode_when_array_is_array_of_enums(my_enum):
 def test_enum_encode_when_array_is_scalar_array_of_enum(my_enum):
     values = array(my_enum.bar)
 
-    result = my_enum.encode(values)
-
-    assert result == 1
+    with pytest.raises(TypeError):
+        my_enum.encode(values)
 
 
 def test_enum_encode_when_array_is_array_of_indices(my_enum):
@@ -85,8 +84,8 @@ def test_enum_encode_when_array_is_not_a_data_structure(my_enum):
 
 
 def test_enum_array___eq__(my_enum):
-    enum_array1 = EnumArray(array(1), my_enum)
-    enum_array2 = EnumArray(array(1), my_enum)
+    enum_array1 = EnumArray([array(1)], my_enum)
+    enum_array2 = EnumArray([array(1)], my_enum)
 
     result = enum_array1 == enum_array2
 
@@ -94,8 +93,8 @@ def test_enum_array___eq__(my_enum):
 
 
 def test_enum_array___ne__(my_enum):
-    enum_array1 = EnumArray(array(0), my_enum)
-    enum_array2 = EnumArray(array(1), my_enum)
+    enum_array1 = EnumArray([array(0)], my_enum)
+    enum_array2 = EnumArray([array(1)], my_enum)
 
     result = enum_array1 != enum_array2
 
@@ -103,14 +102,14 @@ def test_enum_array___ne__(my_enum):
 
 
 def test_enum_array__forbidden_operation(my_enum):
-    enum_array = EnumArray(array(1), my_enum)
+    enum_array = EnumArray([array(1)], my_enum)
 
     with pytest.raises(TypeError):
         enum_array * 1
 
 
 def test_enum_array_decode(my_enum):
-    values = array(my_enum.bar)
+    values = array([my_enum.bar])
     enum_array = my_enum.encode(values)
 
     result = enum_array.decode()
@@ -119,7 +118,7 @@ def test_enum_array_decode(my_enum):
 
 
 def test_enum_array_decode_to_str(my_enum):
-    values = array(my_enum.bar.value)
+    values = array([my_enum.bar.value])
     enum_array = my_enum.encode(values)
 
     result = enum_array.decode_to_str()
@@ -128,16 +127,16 @@ def test_enum_array_decode_to_str(my_enum):
 
 
 def test_enum_array___repr__(my_enum):
-    enum_array = EnumArray(array(1), my_enum)
+    enum_array = EnumArray([array(1)], my_enum)
 
     result = repr(enum_array)
 
-    assert result == "EnumArray(MyEnum.bar)"
+    assert result == "EnumArray([<MyEnum.bar: 'bar'>])"
 
 
 def test_enum_array___str__(my_enum):
-    enum_array = EnumArray(array(1), my_enum)
+    enum_array = EnumArray([array(1)], my_enum)
 
     result = str(enum_array)
 
-    assert result == "bar"
+    assert result == "['bar']"