diff --git a/image_prediction/formatter/formatter.py b/image_prediction/formatter/formatter.py
index 6c5b97f..3f3a1f8 100644
--- a/image_prediction/formatter/formatter.py
+++ b/image_prediction/formatter/formatter.py
@@ -9,7 +9,7 @@ class Formatter(Transformer):
         raise NotImplementedError
 
     def transform(self, obj):
-        return self.format(obj)
+        raise NotImplementedError()
 
     def __call__(self, obj):
         return self.format(obj)
diff --git a/image_prediction/formatter/formatters/enum.py b/image_prediction/formatter/formatters/enum.py
index f719ead..a412b31 100644
--- a/image_prediction/formatter/formatters/enum.py
+++ b/image_prediction/formatter/formatters/enum.py
@@ -1,13 +1,10 @@
 from enum import Enum
 from typing import List
 
-from image_prediction.formatter.formatter import Formatter
+from image_prediction.formatter.formatters.key_formatter import KeyFormatter
 
 
-class EnumFormatter(Formatter):
+class EnumFormatter(KeyFormatter):
     @staticmethod
-    def __format(metadata: dict):
-        return {key.value if isinstance(key, Enum) else key: val for key, val in metadata.items()}
-
-    def format(self, metadata: List[dict]):
-        return map(self.__format, metadata)
+    def format_key(key):
+        return key.value if isinstance(key, Enum) else key
diff --git a/test/unit_tests/conftest.py b/test/unit_tests/conftest.py
index 9f7c5c7..dc31663 100644
--- a/test/unit_tests/conftest.py
+++ b/test/unit_tests/conftest.py
@@ -225,6 +225,23 @@ def map_labels(numeric_labels, classes):
     return [classes[nl] for nl in numeric_labels]
 
 
+@pytest.fixture
+def metadata_plus_mapped_prediction(expected_predictions_mapped, metadata):
+    return [{"prediction": epm,  **mdt} for epm, mdt in zip(expected_predictions_mapped, metadata)]
+
+
+@pytest.fixture
+def metadata_formatted_plus_mapped_prediction_formatted(expected_predictions_mapped_and_formatted, metadata_formatted):
+    return [
+        {"prediction": epm,  **mdt} for epm, mdt in zip(expected_predictions_mapped_and_formatted, metadata_formatted)
+    ]
+
+
+@pytest.fixture
+def expected_predictions_mapped_and_formatted(expected_predictions_mapped):
+    return [{k.value: v for k, v in epm.items()} for epm in expected_predictions_mapped]
+
+
 @pytest.fixture
 def metadata(images, info_label_map):
     page_idx = 0
diff --git a/test/unit_tests/formatter_test.py b/test/unit_tests/formatter_test.py
index c222147..b012b9a 100644
--- a/test/unit_tests/formatter_test.py
+++ b/test/unit_tests/formatter_test.py
@@ -4,10 +4,15 @@ from image_prediction.formatter.formatters.camel_case import Snake2CamelCaseKeyF
 from image_prediction.formatter.formatters.enum import EnumFormatter
 
 
-def test_formatter(metadata, metadata_formatted):
+def test_enum_formatter(metadata, metadata_formatted):
     assert list(EnumFormatter()(metadata)) == metadata_formatted
 
 
+@pytest.mark.parametrize("label_format", ["probability"])
+def test_enum_formatter(metadata_plus_mapped_prediction, metadata_formatted_plus_mapped_prediction_formatted):
+    assert list(EnumFormatter()(metadata_plus_mapped_prediction)) == metadata_formatted_plus_mapped_prediction_formatted
+
+
 def test_camel_case_key_formatter(snake_case_data, camel_case_data):
     assert Snake2CamelCaseKeyFormatter()(snake_case_data) == camel_case_data