diff --git a/pyproject.toml b/pyproject.toml
index cb69c5e..74be3c1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,11 +58,11 @@ warn_unused_ignores = true
 [tool.ruff]
 line-length = 100
 select = ["ALL"]
-target-version = "py38"
 
 [tool.ruff.per-file-ignores]
 "sigstore_rekor_types/_internal/*.py" = [
-    "A003", # some fields shadow python builtins
+    "A003",  # some fields shadow python builtins
+    "UP007", # pydantic doesn't support PEP 604 below Python 3.10
 ]
 "test/**/*.py" = [
     "D",    # no docstrings in tests
diff --git a/sigstore_rekor_types/_internal/alpine.py b/sigstore_rekor_types/_internal/alpine.py
index 36ad4c7..51ed5cf 100644
--- a/sigstore_rekor_types/_internal/alpine.py
+++ b/sigstore_rekor_types/_internal/alpine.py
@@ -1,5 +1,5 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:55+00:00
+#   timestamp: 2023-10-04T14:54:07+00:00
 
 from __future__ import annotations
 
diff --git a/sigstore_rekor_types/_internal/cose.py b/sigstore_rekor_types/_internal/cose.py
index a117dfd..f48ee66 100644
--- a/sigstore_rekor_types/_internal/cose.py
+++ b/sigstore_rekor_types/_internal/cose.py
@@ -1,9 +1,10 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:55+00:00
+#   timestamp: 2023-10-04T14:54:07+00:00
 
 from __future__ import annotations
 
 from enum import Enum
+from typing import Optional
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
@@ -29,24 +30,24 @@ class EnvelopeHash(BaseModel):
 
 
 class Data(BaseModel):
-    payload_hash: PayloadHash | None = Field(
+    payload_hash: Optional[PayloadHash] = Field(
         None,
         alias="payloadHash",
         description="Specifies the hash algorithm and value for the content",
     )
-    envelope_hash: EnvelopeHash | None = Field(
+    envelope_hash: Optional[EnvelopeHash] = Field(
         None,
         alias="envelopeHash",
         description="Specifies the hash algorithm and value for the COSE envelope",
     )
-    aad: str | None = Field(
+    aad: Optional[str] = Field(
         None,
         description="Specifies the additional authenticated data required to verify the signature",
     )
 
 
 class CoseV001Schema(BaseModel):
-    message: str | None = Field(None, description="The COSE Sign1 Message")
+    message: Optional[str] = Field(None, description="The COSE Sign1 Message")
     public_key: str = Field(
         ...,
         alias="publicKey",
diff --git a/sigstore_rekor_types/_internal/dsse.py b/sigstore_rekor_types/_internal/dsse.py
index 1de3e2e..3e579e1 100644
--- a/sigstore_rekor_types/_internal/dsse.py
+++ b/sigstore_rekor_types/_internal/dsse.py
@@ -1,9 +1,10 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:56+00:00
+#   timestamp: 2023-10-04T14:54:07+00:00
 
 from __future__ import annotations
 
 from enum import Enum
+from typing import Optional
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
@@ -61,8 +62,8 @@ class PayloadHash(BaseModel):
 
 
 class DsseV001Schema(BaseModel):
-    proposed_content: ProposedContent | None = Field(None, alias="proposedContent")
-    signatures: list[Signature] | None = Field(
+    proposed_content: Optional[ProposedContent] = Field(None, alias="proposedContent")
+    signatures: Optional[list[Signature]] = Field(
         None,
         description=(
             "extracted collection of all signatures of the envelope's payload; elements will be"
@@ -70,14 +71,14 @@ class DsseV001Schema(BaseModel):
         ),
         min_length=1,
     )
-    envelope_hash: EnvelopeHash | None = Field(
+    envelope_hash: Optional[EnvelopeHash] = Field(
         None,
         alias="envelopeHash",
         description=(
             "Specifies the hash algorithm and value encompassing the entire envelope sent to Rekor"
         ),
     )
-    payload_hash: PayloadHash | None = Field(
+    payload_hash: Optional[PayloadHash] = Field(
         None,
         alias="payloadHash",
         description=(
diff --git a/sigstore_rekor_types/_internal/hashedrekord.py b/sigstore_rekor_types/_internal/hashedrekord.py
index 43171c1..346203c 100644
--- a/sigstore_rekor_types/_internal/hashedrekord.py
+++ b/sigstore_rekor_types/_internal/hashedrekord.py
@@ -1,15 +1,16 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:56+00:00
+#   timestamp: 2023-10-04T14:54:08+00:00
 
 from __future__ import annotations
 
 from enum import Enum
+from typing import Optional
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
 
 class PublicKey(BaseModel):
-    content: str | None = Field(
+    content: Optional[str] = Field(
         None,
         description=(
             "Specifies the content of the public key or code signing certificate inline within the"
@@ -19,11 +20,11 @@ class PublicKey(BaseModel):
 
 
 class Signature(BaseModel):
-    content: str | None = Field(
+    content: Optional[str] = Field(
         None,
         description="Specifies the content of the signature inline within the document",
     )
-    public_key: PublicKey | None = Field(
+    public_key: Optional[PublicKey] = Field(
         None,
         alias="publicKey",
         description=(
@@ -46,7 +47,7 @@ class Hash(BaseModel):
 
 
 class Data(BaseModel):
-    hash: Hash | None = Field(
+    hash: Optional[Hash] = Field(
         None,
         description="Specifies the hash algorithm and value for the content",
     )
diff --git a/sigstore_rekor_types/_internal/helm.py b/sigstore_rekor_types/_internal/helm.py
index 9f02a7b..6c0515e 100644
--- a/sigstore_rekor_types/_internal/helm.py
+++ b/sigstore_rekor_types/_internal/helm.py
@@ -1,9 +1,10 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:56+00:00
+#   timestamp: 2023-10-04T14:54:08+00:00
 
 from __future__ import annotations
 
 from enum import Enum
+from typing import Optional
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
@@ -28,7 +29,7 @@ class Hash(BaseModel):
 
 
 class Chart(BaseModel):
-    hash: Hash | None = Field(
+    hash: Optional[Hash] = Field(
         None,
         description="Specifies the hash algorithm and value for the chart",
     )
diff --git a/sigstore_rekor_types/_internal/intoto.py b/sigstore_rekor_types/_internal/intoto.py
index 5b0d139..bd2380b 100644
--- a/sigstore_rekor_types/_internal/intoto.py
+++ b/sigstore_rekor_types/_internal/intoto.py
@@ -1,10 +1,10 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:56+00:00
+#   timestamp: 2023-10-04T14:54:08+00:00
 
 from __future__ import annotations
 
 from enum import Enum
-from typing import Union
+from typing import Optional, Union
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
@@ -30,15 +30,15 @@ class PayloadHash(BaseModel):
 
 
 class Content(BaseModel):
-    envelope: StrictStr | None = Field(None, description="envelope")
-    hash: Hash | None = Field(
+    envelope: Optional[StrictStr] = Field(None, description="envelope")
+    hash: Optional[Hash] = Field(
         None,
         description=(
             "Specifies the hash algorithm and value encompassing the entire signed envelope; this"
             " is computed by the rekor server, client-provided values are ignored"
         ),
     )
-    payload_hash: PayloadHash | None = Field(
+    payload_hash: Optional[PayloadHash] = Field(
         None,
         alias="payloadHash",
         description=(
@@ -58,7 +58,7 @@ class IntotoV001Schema(BaseModel):
 
 
 class Signature(BaseModel):
-    keyid: StrictStr | None = Field(
+    keyid: Optional[StrictStr] = Field(
         None,
         description="optional id of the key used to create the signature",
     )
@@ -71,7 +71,7 @@ class Signature(BaseModel):
 
 
 class Envelope(BaseModel):
-    payload: str | None = Field(None, description="payload of the envelope")
+    payload: Optional[str] = Field(None, description="payload of the envelope")
     payload_type: StrictStr = Field(
         ...,
         alias="payloadType",
@@ -102,13 +102,13 @@ class PayloadHash1(BaseModel):
 
 class Content1(BaseModel):
     envelope: Envelope = Field(..., description="dsse envelope")
-    hash: Hash1 | None = Field(
+    hash: Optional[Hash1] = Field(
         None,
         description=(
             "Specifies the hash algorithm and value encompassing the entire signed envelope"
         ),
     )
-    payload_hash: PayloadHash1 | None = Field(
+    payload_hash: Optional[PayloadHash1] = Field(
         None,
         alias="payloadHash",
         description=(
@@ -122,7 +122,7 @@ class IntotoV002Schema(BaseModel):
 
 
 class IntotoSchema(RootModel[Union[IntotoV001Schema, IntotoV002Schema]]):
-    root: IntotoV001Schema | IntotoV002Schema = Field(
+    root: Union[IntotoV001Schema, IntotoV002Schema] = Field(
         ...,
         description="Intoto for Rekord objects",
         title="Intoto Schema",
diff --git a/sigstore_rekor_types/_internal/jar.py b/sigstore_rekor_types/_internal/jar.py
index 2fd4a7f..e1864ca 100644
--- a/sigstore_rekor_types/_internal/jar.py
+++ b/sigstore_rekor_types/_internal/jar.py
@@ -1,8 +1,10 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:57+00:00
+#   timestamp: 2023-10-04T14:54:08+00:00
 
 from __future__ import annotations
 
+from typing import Optional
+
 from pydantic import BaseModel, Field, RootModel
 
 
@@ -32,7 +34,7 @@ class Signature(BaseModel):
 
 
 class JarV001Schema(BaseModel):
-    signature: Signature | None = Field(
+    signature: Optional[Signature] = Field(
         None,
         description="Information about the included signature in the JAR file",
     )
diff --git a/sigstore_rekor_types/_internal/rekord.py b/sigstore_rekor_types/_internal/rekord.py
index 0f72e0a..8151201 100644
--- a/sigstore_rekor_types/_internal/rekord.py
+++ b/sigstore_rekor_types/_internal/rekord.py
@@ -1,5 +1,5 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:57+00:00
+#   timestamp: 2023-10-04T14:54:09+00:00
 
 from __future__ import annotations
 
diff --git a/sigstore_rekor_types/_internal/rfc3161.py b/sigstore_rekor_types/_internal/rfc3161.py
index b745ea5..d1fa546 100644
--- a/sigstore_rekor_types/_internal/rfc3161.py
+++ b/sigstore_rekor_types/_internal/rfc3161.py
@@ -1,5 +1,5 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:57+00:00
+#   timestamp: 2023-10-04T14:54:09+00:00
 
 from __future__ import annotations
 
diff --git a/sigstore_rekor_types/_internal/rpm.py b/sigstore_rekor_types/_internal/rpm.py
index 903ddb9..1c342d0 100644
--- a/sigstore_rekor_types/_internal/rpm.py
+++ b/sigstore_rekor_types/_internal/rpm.py
@@ -1,5 +1,5 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:57+00:00
+#   timestamp: 2023-10-04T14:54:09+00:00
 
 from __future__ import annotations
 
diff --git a/sigstore_rekor_types/_internal/tuf.py b/sigstore_rekor_types/_internal/tuf.py
index 157b595..112a1e5 100644
--- a/sigstore_rekor_types/_internal/tuf.py
+++ b/sigstore_rekor_types/_internal/tuf.py
@@ -1,9 +1,9 @@
 # generated by datamodel-codegen:
-#   timestamp: 2023-10-03T20:01:58+00:00
+#   timestamp: 2023-10-04T14:54:10+00:00
 
 from __future__ import annotations
 
-from typing import Any
+from typing import Any, Optional
 
 from pydantic import BaseModel, Field, RootModel, StrictStr
 
@@ -23,7 +23,7 @@ class Root(BaseModel):
 
 
 class TufV001Schema(BaseModel):
-    spec_version: StrictStr | None = Field(None, description="TUF specification version")
+    spec_version: Optional[StrictStr] = Field(None, description="TUF specification version")
     metadata: Metadata = Field(..., description="TUF metadata")
     root: Root = Field(
         ...,