diff --git a/dataclasses_json/core.py b/dataclasses_json/core.py
index c7b696e7..91a0b5ff 100644
--- a/dataclasses_json/core.py
+++ b/dataclasses_json/core.py
@@ -135,7 +135,9 @@ def _decode_letter_case_overrides(field_names, overrides):
         if field_override is not None:
             letter_case = field_override.letter_case
             if letter_case is not None:
-                names[letter_case(field_name)] = field_name
+                names[field_name] = letter_case(field_name)
+        if field_name not in names:
+            names[field_name] = field_name
     return names
 
 
@@ -146,7 +148,8 @@ def _decode_dataclass(cls, kvs, infer_missing):
     kvs = {} if kvs is None and infer_missing else kvs
     field_names = [field.name for field in fields(cls)]
     decode_names = _decode_letter_case_overrides(field_names, overrides)
-    kvs = {decode_names.get(k, k): v for k, v in kvs.items()}
+    undefined_fields = {k: v for k, v in kvs.items() if k not in decode_names.values()}
+    kvs = {**{k: kvs[v] for k, v in decode_names.items() if v in kvs}, **undefined_fields}
     missing_fields = {field for field in fields(cls) if field.name not in kvs}
 
     for field in missing_fields:
diff --git a/tests/test_metadata.py b/tests/test_metadata.py
index 980e7903..b0428bf6 100644
--- a/tests/test_metadata.py
+++ b/tests/test_metadata.py
@@ -1,11 +1,12 @@
 import datetime
+import json
 from dataclasses import dataclass, field
-from typing import Optional
+from typing import Optional, Dict
 
 import pytest
 from marshmallow import fields, ValidationError
 
-from dataclasses_json import DataClassJsonMixin
+from dataclasses_json import DataClassJsonMixin, dataclass_json, config
 
 
 @dataclass
@@ -24,7 +25,8 @@ class StringDate(DataClassJsonMixin):
             'decoder': str,
             'mm_field': fields.String(required=False)}
         })
-    
+
+
 @dataclass
 class OptionalStringDate(DataClassJsonMixin):
     string_date: Optional[datetime.datetime] = field(
@@ -36,6 +38,14 @@ class OptionalStringDate(DataClassJsonMixin):
         })
 
 
+@dataclass_json
+@dataclass
+class MyDataClass:
+    first: str = field(metadata=config(field_name="myJsonField", decoder=lambda x: x["first"]))
+    second: str = field(metadata=config(field_name="myJsonField", decoder=lambda x: x["second"]))
+    other_field: str = field(metadata=config(field_name="otherField"))
+
+
 car_schema = Car.schema()
 string_date_schema = StringDate.schema()
 opt_string_date_schema = OptionalStringDate.schema()
@@ -60,3 +70,16 @@ def test_optional_field_only_decoded_when_present(self):
         another_obj = opt_string_date_schema.load({'string_date': 'today'})
         assert isinstance(another_obj, OptionalStringDate)
         assert another_obj.string_date == 'today'
+
+    def test_multiple_fields_same_name(self):
+        contents = json.dumps({
+            "myJsonField": {
+                "first": "val1",
+                "second": "val2"
+            },
+            "otherField": "valotherfield"
+        })
+        obj = MyDataClass.from_json(contents)
+        assert obj.first == "val1"
+        assert obj.second == "val2"
+        assert obj.other_field == "valotherfield"