diff --git a/src/reader/_types.py b/src/reader/_types.py
index e97b402b..dbcdc068 100644
--- a/src/reader/_types.py
+++ b/src/reader/_types.py
@@ -180,6 +180,7 @@ def entry_data_from_obj(obj: object) -> EntryData:
     """
     if isinstance(obj, Mapping):
         obj = SimpleNamespace(**obj)
+    source_obj = getattr(obj, 'source', None)
     return EntryData(
         feed_url=_getattr(obj, 'feed_url', str),
         id=_getattr(obj, 'id', str),
@@ -191,6 +192,7 @@ def entry_data_from_obj(obj: object) -> EntryData:
         summary=_getattr_optional(obj, 'summary', str),
         content=tuple(content_from_obj(o) for o in getattr(obj, 'content', ())),
         enclosures=tuple(enclosure_from_obj(o) for o in getattr(obj, 'enclosures', ())),
+        source=source_from_obj(source_obj) if source_obj else None,
     )
 
 
@@ -214,6 +216,19 @@ def enclosure_from_obj(obj: object) -> Enclosure:
     )
 
 
+def source_from_obj(obj: object) -> EntrySource:
+    if isinstance(obj, Mapping):
+        obj = SimpleNamespace(**obj)
+    return EntrySource(
+        url=_getattr_optional(obj, 'url', str),
+        updated=_getattr_optional_datetime(obj, 'updated'),
+        title=_getattr_optional(obj, 'title', str),
+        link=_getattr_optional(obj, 'link', str),
+        author=_getattr_optional(obj, 'author', str),
+        subtitle=_getattr_optional(obj, 'subtitle', str),
+    )
+
+
 def _getattr(obj: object, name: str, type: type[_T]) -> _T:
     # will raise AttributeError implicitly
     value = getattr(obj, name)
diff --git a/src/reader/core.py b/src/reader/core.py
index 670eccf5..3f1eab28 100644
--- a/src/reader/core.py
+++ b/src/reader/core.py
@@ -1513,6 +1513,7 @@ def add_entry(self, entry: Any, /) -> None:
         * :attr:`~Entry.summary`
         * :attr:`~Entry.content`
         * :attr:`~Entry.enclosures`
+        * :attr:`~Entry.source`
 
         Naive datetimes are normalized by passing them to
         :meth:`~datetime.datetime.astimezone`.
@@ -1532,6 +1533,9 @@ def add_entry(self, entry: Any, /) -> None:
         .. versionchanged:: 3.0
             The ``entry`` argument is now positional-only.
 
+        .. versionchanged:: 3.16
+            Allow setting :attr:`~Entry.source`.
+
         """
 
         # `entry` is of type Union[EntryDataLikeProtocol, EntryDataTypedDict],
diff --git a/tests/test__types.py b/tests/test__types.py
index e9b9ec51..5fa4ab7f 100644
--- a/tests/test__types.py
+++ b/tests/test__types.py
@@ -88,15 +88,13 @@ def test_tristate_filter_argument_error(input):
     assert 'name' in str(excinfo.value)
 
 
+@pytest.mark.parametrize('feed_type', ['rss', 'atom'])
 @pytest.mark.parametrize('data_file', ['full', 'empty'])
-def test_entry_data_from_obj(data_dir, data_file):
+def test_entry_data_from_obj(data_dir, feed_type, data_file):
     expected = {'url_base': '', 'rel_base': ''}
-    exec(data_dir.joinpath(f'{data_file}.rss.py').read_bytes(), expected)
+    exec(data_dir.joinpath(f'{data_file}.{feed_type}.py').read_bytes(), expected)
 
     for i, entry in enumerate(expected['entries']):
-        # FIXME: temporary during #276 development
-        entry = entry._replace(source=None)
-
         assert entry == entry_data_from_obj(entry), i
 
         entry_dict = entry._asdict()
@@ -104,6 +102,8 @@ def test_entry_data_from_obj(data_dir, data_file):
             entry_dict['content'] = [c._asdict() for c in entry_dict['content']]
         if 'enclosures' in entry_dict:
             entry_dict['enclosures'] = [e._asdict() for e in entry_dict['enclosures']]
+        if entry_dict.get('source'):
+            entry_dict['source'] = entry_dict['source']._asdict()
 
         assert entry == entry_data_from_obj(entry_dict), i