diff --git a/dcargs/extras/_serialization.py b/dcargs/extras/_serialization.py
index c4ba73a4..c5c433a4 100644
--- a/dcargs/extras/_serialization.py
+++ b/dcargs/extras/_serialization.py
@@ -2,10 +2,11 @@
 
 import dataclasses
 import enum
+import functools
 from typing import IO, Any, Optional, Set, Type, TypeVar, Union
 
 import yaml
-from typing_extensions import get_origin
+from typing_extensions import get_args, get_origin
 
 from .. import _fields, _resolver
 
@@ -48,15 +49,21 @@ def _get_contained_special_types_from_type(
     contained_dataclasses = {cls}
 
     def handle_type(typ) -> Set[Type]:
+        print(typ)
+        # Handle dataclasses.
         if _resolver.is_dataclass(typ) and typ not in parent_contained_dataclasses:
             return _get_contained_special_types_from_type(
                 typ,
                 _parent_contained_dataclasses=contained_dataclasses
                 | parent_contained_dataclasses,
             )
+
+        # Handle enums.
         elif type(typ) is enum.EnumMeta:
             return {typ}
-        return set()
+
+        # Handle Union, Annotated, List, etc. No-op when there are no args.
+        return functools.reduce(set.union, map(handle_type, get_args(typ)), set())
 
     # Handle generics.
     for typ in type_from_typevar.values():
diff --git a/pyproject.toml b/pyproject.toml
index 7dd66399..cda21fa8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "dcargs"
-version = "0.2.6"
+version = "0.2.7"
 description = "Strongly typed, zero-effort CLI interfaces"
 authors = ["brentyi <brentyi@berkeley.edu>"]
 include = ["./dcargs/**/*"]
diff --git a/tests/test_generics_and_serialization.py b/tests/test_generics_and_serialization.py
index 0ac23f7c..c8d4e65f 100644
--- a/tests/test_generics_and_serialization.py
+++ b/tests/test_generics_and_serialization.py
@@ -5,6 +5,7 @@
 from typing import Generic, List, Tuple, Type, TypeVar, Union
 
 import pytest
+from typing_extensions import Annotated
 
 import dcargs
 
@@ -346,3 +347,43 @@ def main(x: ActualParentClass[int] = ChildClass(5, 5)) -> ActualParentClass:
         return x
 
     assert dcargs.cli(main, args="--x.x 3".split(" ")) == ChildClass(3, 5, 3)
+
+
+def test_pculbertson():
+    # https://github.com/brentyi/dcargs/issues/7
+    from typing import Union
+
+    @dataclasses.dataclass
+    class TypeA:
+        data: int
+
+    @dataclasses.dataclass
+    class TypeB:
+        data: int
+
+    @dataclasses.dataclass
+    class Wrapper:
+        subclass: Union[TypeA, TypeB] = TypeA(1)
+
+    wrapper1 = Wrapper()  # Create Wrapper object.
+    wrapper2 = dcargs.extras.from_yaml(
+        Wrapper, dcargs.extras.to_yaml(wrapper1)
+    )  # Errors, no constructor for TypeA
+
+
+def test_annotated():
+    # https://github.com/brentyi/dcargs/issues/7
+    from typing import Union
+
+    @dataclasses.dataclass
+    class TypeA:
+        data: int
+
+    @dataclasses.dataclass
+    class Wrapper:
+        subclass: Annotated[int, TypeA] = TypeA(1)
+
+    wrapper1 = Wrapper()  # Create Wrapper object.
+    wrapper2 = dcargs.extras.from_yaml(
+        Wrapper, dcargs.extras.to_yaml(wrapper1)
+    )  # Errors, no constructor for TypeA