diff --git a/docs/source/changelog.md b/docs/source/changelog.md
index 21dd0bfc..f4133e04 100644
--- a/docs/source/changelog.md
+++ b/docs/source/changelog.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.9.9 (XXXX-XX-XX)
+- Support using subclasses of lists, tuple, and dict via deep_map. This allows usage of NamedTuple for more
+    semantically obvious return types.
+
 ## 0.9.8 (2024-09-06)
 - Bugfix for `inputs` argument for `flow.run()`.
 
diff --git a/src/pydiverse/pipedag/util/deep_map.py b/src/pydiverse/pipedag/util/deep_map.py
index 5c4aef9d..8770ad4c 100644
--- a/src/pydiverse/pipedag/util/deep_map.py
+++ b/src/pydiverse/pipedag/util/deep_map.py
@@ -3,6 +3,7 @@
 Heavily inspired by the builtin copy module of python:
 https://github.com/python/cpython/blob/main/Lib/copy.py
 """
+
 from __future__ import annotations
 
 from typing import Callable
@@ -19,13 +20,11 @@ def deep_map(x, fn: Callable, memo=None):
     if y is not _nil:
         return y
 
-    cls = type(x)
-
-    if cls == list:
+    if isinstance(x, list):
         y = _deep_map_list(x, fn, memo)
-    elif cls == tuple:
+    elif isinstance(x, tuple):
         y = _deep_map_tuple(x, fn, memo)
-    elif cls == dict:
+    elif isinstance(x, dict):
         y = _deep_map_dict(x, fn, memo)
     else:
         y = fn(x)
diff --git a/tests/test_flows/test_flow.py b/tests/test_flows/test_flow.py
index 3921c840..34bfe7aa 100644
--- a/tests/test_flows/test_flow.py
+++ b/tests/test_flows/test_flow.py
@@ -1,4 +1,5 @@
 from __future__ import annotations
+from typing import NamedTuple
 
 import pandas as pd
 import sqlalchemy as sa
@@ -46,9 +47,14 @@ def list_arg(x: list[pd.DataFrame]):
     return Blob(x)
 
 
+class Blobs(NamedTuple):
+    a: Blob
+    b: Blob
+
+
 @materialize
 def blob_task(x, y):
-    return Blob(x), Blob(y)
+    return Blobs(Blob(x), Blob(y))
 
 
 def test_simple_flow(with_blob=True):