diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 55d2025..ff261ba 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -3,7 +3,7 @@ FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
 
 USER vscode
 
-RUN curl -sSf https://rye.astral.sh/get | RYE_VERSION="0.35.0" RYE_INSTALL_OPTION="--yes" bash
+RUN curl -sSf https://rye.astral.sh/get | RYE_VERSION="0.44.0" RYE_INSTALL_OPTION="--yes" bash
 ENV PATH=/home/vscode/.rye/shims:$PATH
 
 RUN echo "[[ -d .venv ]] && source .venv/bin/activate || export PATH=\$PATH" >> /home/vscode/.bashrc
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c8a8a4f..3b286e5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@ jobs:
           curl -sSf https://rye.astral.sh/get | bash
           echo "$HOME/.rye/shims" >> $GITHUB_PATH
         env:
-          RYE_VERSION: '0.35.0'
+          RYE_VERSION: '0.44.0'
           RYE_INSTALL_OPTION: '--yes'
 
       - name: Install dependencies
@@ -42,7 +42,7 @@ jobs:
           curl -sSf https://rye.astral.sh/get | bash
           echo "$HOME/.rye/shims" >> $GITHUB_PATH
         env:
-          RYE_VERSION: '0.35.0'
+          RYE_VERSION: '0.44.0'
           RYE_INSTALL_OPTION: '--yes'
 
       - name: Bootstrap
diff --git a/.github/workflows/publish-pypi.yml b/.github/workflows/publish-pypi.yml
index 3e178a6..13dc1e5 100644
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -21,7 +21,7 @@ jobs:
           curl -sSf https://rye.astral.sh/get | bash
           echo "$HOME/.rye/shims" >> $GITHUB_PATH
         env:
-          RYE_VERSION: '0.35.0'
+          RYE_VERSION: '0.44.0'
           RYE_INSTALL_OPTION: '--yes'
 
       - name: Publish to PyPI
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 9ffa609..dc8ed9b 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.8.3"
+  ".": "1.8.4"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index d4b713b..2de8424 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,2 +1,4 @@
 configured_endpoints: 29
 openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/open-transit%2Fopen-transit-6f08502508c8ad25235971add3124a1cde4f1c3ec705d5df455d750e0adcb90b.yml
+openapi_spec_hash: 84d082f35446d29c7db3cfcd259e9859
+config_hash: c7e112ec9853ad18fe92551ae0d97656
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 879b685..3934b2e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,22 @@
 # Changelog
 
+## 1.8.4 (2025-03-27)
+
+Full Changelog: [v1.8.3...v1.8.4](https://github.com/OneBusAway/python-sdk/compare/v1.8.3...v1.8.4)
+
+### Bug Fixes
+
+* **ci:** ensure pip is always available ([#284](https://github.com/OneBusAway/python-sdk/issues/284)) ([959d15e](https://github.com/OneBusAway/python-sdk/commit/959d15edcf912b2742e3598a35396041492ecbb7))
+* **ci:** remove publishing patch ([#285](https://github.com/OneBusAway/python-sdk/issues/285)) ([43691e0](https://github.com/OneBusAway/python-sdk/commit/43691e0b16c2c885b8e75d07e82f1ff26d961ac8))
+* **types:** handle more discriminated union shapes ([#283](https://github.com/OneBusAway/python-sdk/issues/283)) ([d55c08a](https://github.com/OneBusAway/python-sdk/commit/d55c08ad0ff636bf899c7a989185f30f431649bb))
+
+
+### Chores
+
+* fix typos ([#286](https://github.com/OneBusAway/python-sdk/issues/286)) ([e45e047](https://github.com/OneBusAway/python-sdk/commit/e45e04798e64b912d4ba598ebc3ef0cdaf031203))
+* **internal:** bump rye to 0.44.0 ([#282](https://github.com/OneBusAway/python-sdk/issues/282)) ([217ce3f](https://github.com/OneBusAway/python-sdk/commit/217ce3f97be80d4861ffc277336ec196c6873788))
+* **internal:** remove extra empty newlines ([#280](https://github.com/OneBusAway/python-sdk/issues/280)) ([3ca5c73](https://github.com/OneBusAway/python-sdk/commit/3ca5c734669aad9252aca2761537f2cf6dc9cfab))
+
 ## 1.8.3 (2025-03-04)
 
 Full Changelog: [v1.8.2...v1.8.3](https://github.com/OneBusAway/python-sdk/compare/v1.8.2...v1.8.3)
diff --git a/bin/publish-pypi b/bin/publish-pypi
index 05bfccb..826054e 100644
--- a/bin/publish-pypi
+++ b/bin/publish-pypi
@@ -3,7 +3,4 @@
 set -eux
 mkdir -p dist
 rye build --clean
-# Patching importlib-metadata version until upstream library version is updated
-# https://github.com/pypa/twine/issues/977#issuecomment-2189800841
-"$HOME/.rye/self/bin/python3" -m pip install 'importlib-metadata==7.2.1'
 rye publish --yes --token=$PYPI_TOKEN
diff --git a/pyproject.toml b/pyproject.toml
index 1f496a3..6b048b7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "onebusaway"
-version = "1.8.3"
+version = "1.8.4"
 description = "The official Python library for the onebusaway-sdk API"
 dynamic = ["readme"]
 license = "Apache-2.0"
@@ -38,7 +38,6 @@ Homepage = "https://github.com/OneBusAway/python-sdk"
 Repository = "https://github.com/OneBusAway/python-sdk"
 
 
-
 [tool.rye]
 managed = true
 # version pins are in requirements-dev.lock
@@ -87,7 +86,7 @@ typecheck = { chain = [
 "typecheck:mypy" = "mypy ."
 
 [build-system]
-requires = ["hatchling", "hatch-fancy-pypi-readme"]
+requires = ["hatchling==1.26.3", "hatch-fancy-pypi-readme"]
 build-backend = "hatchling.build"
 
 [tool.hatch.build]
@@ -152,7 +151,6 @@ reportImplicitOverride = true
 reportImportCycles = false
 reportPrivateUsage = false
 
-
 [tool.ruff]
 line-length = 120
 output-format = "grouped"
diff --git a/scripts/test b/scripts/test
index 4fa5698..2b87845 100755
--- a/scripts/test
+++ b/scripts/test
@@ -52,6 +52,8 @@ else
   echo
 fi
 
+export DEFER_PYDANTIC_BUILD=false
+
 echo "==> Running tests"
 rye run pytest "$@"
 
diff --git a/src/onebusaway/_models.py b/src/onebusaway/_models.py
index c4401ff..3493571 100644
--- a/src/onebusaway/_models.py
+++ b/src/onebusaway/_models.py
@@ -65,7 +65,7 @@
 from ._constants import RAW_RESPONSE_HEADER
 
 if TYPE_CHECKING:
-    from pydantic_core.core_schema import ModelField, LiteralSchema, ModelFieldsSchema
+    from pydantic_core.core_schema import ModelField, ModelSchema, LiteralSchema, ModelFieldsSchema
 
 __all__ = ["BaseModel", "GenericModel"]
 
@@ -646,15 +646,18 @@ def _build_discriminated_union_meta(*, union: type, meta_annotations: tuple[Any,
 
 def _extract_field_schema_pv2(model: type[BaseModel], field_name: str) -> ModelField | None:
     schema = model.__pydantic_core_schema__
+    if schema["type"] == "definitions":
+        schema = schema["schema"]
+
     if schema["type"] != "model":
         return None
 
+    schema = cast("ModelSchema", schema)
     fields_schema = schema["schema"]
     if fields_schema["type"] != "model-fields":
         return None
 
     fields_schema = cast("ModelFieldsSchema", fields_schema)
-
     field = fields_schema["fields"].get(field_name)
     if not field:
         return None
@@ -678,7 +681,7 @@ def set_pydantic_config(typ: Any, config: pydantic.ConfigDict) -> None:
     setattr(typ, "__pydantic_config__", config)  # noqa: B010
 
 
-# our use of subclasssing here causes weirdness for type checkers,
+# our use of subclassing here causes weirdness for type checkers,
 # so we just pretend that we don't subclass
 if TYPE_CHECKING:
     GenericModel = BaseModel
diff --git a/src/onebusaway/_utils/_transform.py b/src/onebusaway/_utils/_transform.py
index 18afd9d..7ac2e17 100644
--- a/src/onebusaway/_utils/_transform.py
+++ b/src/onebusaway/_utils/_transform.py
@@ -126,7 +126,7 @@ def _get_annotated_type(type_: type) -> type | None:
 def _maybe_transform_key(key: str, type_: type) -> str:
     """Transform the given `data` based on the annotations provided in `type_`.
 
-    Note: this function only looks at `Annotated` types that contain `PropertInfo` metadata.
+    Note: this function only looks at `Annotated` types that contain `PropertyInfo` metadata.
     """
     annotated_type = _get_annotated_type(type_)
     if annotated_type is None:
diff --git a/src/onebusaway/_version.py b/src/onebusaway/_version.py
index af5f659..e4402cd 100644
--- a/src/onebusaway/_version.py
+++ b/src/onebusaway/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "onebusaway"
-__version__ = "1.8.3"  # x-release-please-version
+__version__ = "1.8.4"  # x-release-please-version
diff --git a/tests/test_models.py b/tests/test_models.py
index 95fa41d..d3499d2 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -854,3 +854,35 @@ class Model(BaseModel):
     m = construct_type(value={"cls": "foo"}, type_=Model)
     assert isinstance(m, Model)
     assert isinstance(m.cls, str)
+
+
+def test_discriminated_union_case() -> None:
+    class A(BaseModel):
+        type: Literal["a"]
+
+        data: bool
+
+    class B(BaseModel):
+        type: Literal["b"]
+
+        data: List[Union[A, object]]
+
+    class ModelA(BaseModel):
+        type: Literal["modelA"]
+
+        data: int
+
+    class ModelB(BaseModel):
+        type: Literal["modelB"]
+
+        required: str
+
+        data: Union[A, B]
+
+    # when constructing ModelA | ModelB, value data doesn't match ModelB exactly - missing `required`
+    m = construct_type(
+        value={"type": "modelB", "data": {"type": "a", "data": True}},
+        type_=cast(Any, Annotated[Union[ModelA, ModelB], PropertyInfo(discriminator="type")]),
+    )
+
+    assert isinstance(m, ModelB)