diff --git a/nodebook/pickledict.py b/nodebook/pickledict.py
index 01740f4..33a32e3 100644
--- a/nodebook/pickledict.py
+++ b/nodebook/pickledict.py
@@ -66,7 +66,6 @@ class PickleDict(DictMixin):
         persist_path: if provided, perform serialization to/from disk to this path
         """
         self.persist_path = persist_path
-        self.encodings = {}
         self.dump = partial(msgpack.dump, default=msgpack_serialize)
         self.load = partial(msgpack.load, ext_hook=msgpack_deserialize)
         self.dict = {}
@@ -96,25 +95,21 @@ class PickleDict(DictMixin):
         if self.persist_path is not None:
             path = self.dict[key]
             with open(path, 'rb') as f:
-                value = self.load(f, encoding=self.encodings[key])
+                value = self.load(f, raw=False)
         else:
             f = StringIO(self.dict[key])
-            value = self.load(f, encoding=self.encodings[key])
+            value = self.load(f, raw=False)
         return value
 
     def __setitem__(self, key, value):
-        encoding = None
-        if isinstance(value, six.string_types):
-            encoding = 'utf-8'
-        self.encodings[key] = encoding
         if self.persist_path is not None:
             path = os.path.join(self.persist_path, '%s.pak' % key)
             with open(path, 'wb') as f:
-                self.dump(value, f, encoding=encoding)
+                self.dump(value, f, strict_types=True, use_bin_type=True)
             self.dict[key] = path
         else:
             f = StringIO()
-            self.dump(value, f, encoding=encoding)
+            self.dump(value, f, strict_types=True, use_bin_type=True)
             serialized = f.getvalue()
             self.dict[key] = serialized
 
diff --git a/setup.py b/setup.py
index d54a7f5..eb22642 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@ import sys
 
 setup(
     name='nodebook',
-    version='0.3.0',
+    version='0.3.1',
     author='Kevin Zielnicki',
     author_email='kzielnicki@stitchfix.com',
     license='Stitch Fix 2018',

In python3, strings in dictionaries are de-serialized as bytes
Eg, `foo = {'key':42}` is deserialized as `{b'key':42}`
diff --git a/tests/test_pickledict.py b/tests/test_pickledict.py
index 30ac34b..de2cc45 100644
--- a/tests/test_pickledict.py
+++ b/tests/test_pickledict.py
@@ -25,10 +25,33 @@ class TestPickleDict(object):
         mydict['test_string'] = 'foo'
         assert mydict['test_string'] == 'foo'
 
+        d = {'foo':'bar'}
+        mydict['test_string_dict'] = d
+        assert mydict['test_string_dict'] == d
+
     def test_bytes(self, mydict):
         mydict['test_bytes'] = b'foo'
         assert mydict['test_bytes'] == b'foo'
 
+        d = {b'foo':b'bar'}
+        mydict['test_bytes_dict'] = d
+        assert mydict['test_bytes_dict'] == d
+
+    def test_list(self, mydict):
+        l = [1,2,3]
+        mydict['test_list'] = l
+        assert mydict['test_list'] == l
+
+    def test_tuple(self, mydict):
+        t = (1,2,3)
+        mydict['test_tuple'] = t
+        assert mydict['test_tuple'] == t
+
+    def test_set(self, mydict):
+        s = {1,2,3}
+        mydict['test_set'] = s
+        assert mydict['test_set'] == s
+
     def test_df(self, mydict):
         df = pd.DataFrame({'a': [0, 1, 2], 'b': ['foo', 'bar', 'baz']})
         mydict['test_df'] = df

pip install -e .
parse_log_pytest
pytest
pytest
apt-get update apt-get install -y gcc
3.9
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
anyio==4.9.0
argon2-cffi==23.1.0
argon2-cffi-bindings==21.2.0
arrow==1.3.0
asttokens==3.0.0
async-lru==2.0.5
attrs==25.3.0
babel==2.17.0
beautifulsoup4==4.13.3
bleach==6.2.0
certifi==2025.1.31
cffi==1.17.1
charset-normalizer==3.4.1
click==8.1.8
cloudpickle==3.1.1
comm==0.2.2
debugpy==1.8.13
decorator==5.2.1
defusedxml==0.7.1
exceptiongroup @ file:///croot/exceptiongroup_1706031385326/work
executing==2.2.0
fastjsonschema==2.21.1
fqdn==1.5.1
h11==0.14.0
httpcore==1.0.7
httpx==0.28.1
idna==3.10
importlib_metadata==8.6.1
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
ipykernel==6.29.5
ipython==8.18.1
ipywidgets==8.1.5
isoduration==20.11.0
jedi==0.19.2
Jinja2==3.1.6
json5==0.10.0
jsonpointer==3.0.0
jsonschema==4.23.0
jsonschema-specifications==2024.10.1
jupyter==1.1.1
jupyter-console==6.6.3
jupyter-events==0.12.0
jupyter-lsp==2.2.5
jupyter_client==8.6.3
jupyter_core==5.7.2
jupyter_server==2.15.0
jupyter_server_terminals==0.5.3
jupyterlab==4.3.6
jupyterlab_pygments==0.3.0
jupyterlab_server==2.27.3
jupyterlab_widgets==3.0.13
MarkupSafe==3.0.2
matplotlib-inline==0.1.7
mistune==3.1.3
msgpack-python==0.5.6
nbclient==0.10.2
nbconvert==7.16.6
nbformat==5.10.4
nest-asyncio==1.6.0
-e git+https://github.com/stitchfix/nodebook.git@6ddc1a7f5e47a80060365bfb1b9012b928f68970#egg=nodebook
notebook==7.3.3
notebook_shim==0.2.4
numpy==2.0.2
overrides==7.7.0
packaging @ file:///croot/packaging_1734472117206/work
pandas==2.2.3
pandocfilters==1.5.1
parso==0.8.4
pexpect==4.9.0
platformdirs==4.3.7
pluggy @ file:///croot/pluggy_1733169602837/work
prometheus_client==0.21.1
prompt_toolkit==3.0.50
psutil==7.0.0
ptyprocess==0.7.0
pure_eval==0.2.3
pycparser==2.22
Pygments==2.19.1
pytest @ file:///croot/pytest_1738938843180/work
pytest-runner==6.0.1
python-dateutil==2.9.0.post0
python-json-logger==3.3.0
pytz==2025.2
PyYAML==6.0.2
pyzmq==26.3.0
referencing==0.36.2
requests==2.32.3
rfc3339-validator==0.1.4
rfc3986-validator==0.1.1
rpds-py==0.24.0
Send2Trash==1.8.3
six==1.17.0
sniffio==1.3.1
soupsieve==2.6
stack-data==0.6.3
terminado==0.18.1
tinycss2==1.4.0
tomli @ file:///opt/conda/conda-bld/tomli_1657175507142/work
tornado==6.4.2
traitlets==5.14.3
types-python-dateutil==2.9.0.20241206
typing_extensions==4.13.0
tzdata==2025.2
uri-template==1.3.0
urllib3==2.3.0
wcwidth==0.2.13
webcolors==24.11.1
webencodings==0.5.1
websocket-client==1.8.0
widgetsnbextension==4.0.13
zipp==3.21.0

name: nodebook
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - exceptiongroup=1.2.0=py39h06a4308_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - packaging=24.2=py39h06a4308_0
  - pip=25.0=py39h06a4308_0
  - pluggy=1.5.0=py39h06a4308_0
  - pytest=8.3.4=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tomli=2.0.1=py39h06a4308_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - anyio==4.9.0
      - argon2-cffi==23.1.0
      - argon2-cffi-bindings==21.2.0
      - arrow==1.3.0
      - asttokens==3.0.0
      - async-lru==2.0.5
      - attrs==25.3.0
      - babel==2.17.0
      - beautifulsoup4==4.13.3
      - bleach==6.2.0
      - certifi==2025.1.31
      - cffi==1.17.1
      - charset-normalizer==3.4.1
      - click==8.1.8
      - cloudpickle==3.1.1
      - comm==0.2.2
      - debugpy==1.8.13
      - decorator==5.2.1
      - defusedxml==0.7.1
      - executing==2.2.0
      - fastjsonschema==2.21.1
      - fqdn==1.5.1
      - h11==0.14.0
      - httpcore==1.0.7
      - httpx==0.28.1
      - idna==3.10
      - importlib-metadata==8.6.1
      - ipykernel==6.29.5
      - ipython==8.18.1
      - ipywidgets==8.1.5
      - isoduration==20.11.0
      - jedi==0.19.2
      - jinja2==3.1.6
      - json5==0.10.0
      - jsonpointer==3.0.0
      - jsonschema==4.23.0
      - jsonschema-specifications==2024.10.1
      - jupyter==1.1.1
      - jupyter-client==8.6.3
      - jupyter-console==6.6.3
      - jupyter-core==5.7.2
      - jupyter-events==0.12.0
      - jupyter-lsp==2.2.5
      - jupyter-server==2.15.0
      - jupyter-server-terminals==0.5.3
      - jupyterlab==4.3.6
      - jupyterlab-pygments==0.3.0
      - jupyterlab-server==2.27.3
      - jupyterlab-widgets==3.0.13
      - markupsafe==3.0.2
      - matplotlib-inline==0.1.7
      - mistune==3.1.3
      - msgpack-python==0.5.6
      - nbclient==0.10.2
      - nbconvert==7.16.6
      - nbformat==5.10.4
      - nest-asyncio==1.6.0
      - notebook==7.3.3
      - notebook-shim==0.2.4
      - numpy==2.0.2
      - overrides==7.7.0
      - pandas==2.2.3
      - pandocfilters==1.5.1
      - parso==0.8.4
      - pexpect==4.9.0
      - platformdirs==4.3.7
      - prometheus-client==0.21.1
      - prompt-toolkit==3.0.50
      - psutil==7.0.0
      - ptyprocess==0.7.0
      - pure-eval==0.2.3
      - pycparser==2.22
      - pygments==2.19.1
      - pytest-runner==6.0.1
      - python-dateutil==2.9.0.post0
      - python-json-logger==3.3.0
      - pytz==2025.2
      - pyyaml==6.0.2
      - pyzmq==26.3.0
      - referencing==0.36.2
      - requests==2.32.3
      - rfc3339-validator==0.1.4
      - rfc3986-validator==0.1.1
      - rpds-py==0.24.0
      - send2trash==1.8.3
      - six==1.17.0
      - sniffio==1.3.1
      - soupsieve==2.6
      - stack-data==0.6.3
      - terminado==0.18.1
      - tinycss2==1.4.0
      - tornado==6.4.2
      - traitlets==5.14.3
      - types-python-dateutil==2.9.0.20241206
      - typing-extensions==4.13.0
      - tzdata==2025.2
      - uri-template==1.3.0
      - urllib3==2.3.0
      - wcwidth==0.2.13
      - webcolors==24.11.1
      - webencodings==0.5.1
      - websocket-client==1.8.0
      - widgetsnbextension==4.0.13
      - zipp==3.21.0
prefix: /opt/conda/envs/nodebook

tests/test_pickledict.py::TestPickleDict::test_string[mode_memory] tests/test_pickledict.py::TestPickleDict::test_string[mode_disk] tests/test_pickledict.py::TestPickleDict::test_tuple[mode_memory] tests/test_pickledict.py::TestPickleDict::test_tuple[mode_disk]
tests/test_pickledict.py::TestPickleDict::test_int[mode_memory] tests/test_pickledict.py::TestPickleDict::test_int[mode_disk] tests/test_pickledict.py::TestPickleDict::test_bytes[mode_memory] tests/test_pickledict.py::TestPickleDict::test_bytes[mode_disk] tests/test_pickledict.py::TestPickleDict::test_list[mode_memory] tests/test_pickledict.py::TestPickleDict::test_list[mode_disk] tests/test_pickledict.py::TestPickleDict::test_set[mode_memory] tests/test_pickledict.py::TestPickleDict::test_set[mode_disk] tests/test_pickledict.py::TestPickleDict::test_df[mode_memory] tests/test_pickledict.py::TestPickleDict::test_df[mode_disk] tests/test_pickledict.py::TestPickleDict::test_func[mode_memory] tests/test_pickledict.py::TestPickleDict::test_func[mode_disk] tests/test_pickledict.py::TestPickleDict::test_closure[mode_memory] tests/test_pickledict.py::TestPickleDict::test_closure[mode_disk] tests/test_pickledict.py::TestPickleDict::test_immutability[mode_memory] tests/test_pickledict.py::TestPickleDict::test_immutability[mode_disk]
setup.py nodebook/pickledict.py
setup.py nodebook/pickledict.py