diff --git a/src/plyngent/lmproto/openai/model.py b/src/plyngent/lmproto/openai/model.py
index 7cb464b..2d1a631 100644
--- a/src/plyngent/lmproto/openai/model.py
+++ b/src/plyngent/lmproto/openai/model.py
@@ -232,24 +232,24 @@ class Response(Struct, omit_defaults=True):
     output: list[dict[str, Any]]
     object: Literal["response"] = "response"
     status: ResponseStatus | Unset = UNSET
-    error: ResponseError | None | Unset = UNSET
-    incomplete_details: ResponseIncompleteDetails | None | Unset = UNSET
-    instructions: str | list[dict[str, Any]] | None | Unset = UNSET
-    metadata: dict[str, str] | None | Unset = UNSET
+    error: ResponseError | Unset | None = UNSET
+    incomplete_details: ResponseIncompleteDetails | Unset | None = UNSET
+    instructions: str | list[dict[str, Any]] | Unset | None = UNSET
+    metadata: dict[str, str] | Unset | None = UNSET
     parallel_tool_calls: bool | Unset = UNSET
-    temperature: float | None | Unset = UNSET
-    top_p: float | None | Unset = UNSET
+    temperature: float | Unset | None = UNSET
+    top_p: float | Unset | None = UNSET
     tools: list[dict[str, Any]] | Unset = UNSET
     tool_choice: str | dict[str, Any] | Unset = UNSET
     # Prefer loose dict — nested usage details vary by model/API version.
-    usage: dict[str, Any] | None | Unset = UNSET
-    previous_response_id: str | None | Unset = UNSET
-    service_tier: ServiceTier | None | Unset = UNSET
-    truncation: TruncationMode | None | Unset = UNSET
+    usage: dict[str, Any] | Unset | None = UNSET
+    previous_response_id: str | Unset | None = UNSET
+    service_tier: ServiceTier | Unset | None = UNSET
+    truncation: TruncationMode | Unset | None = UNSET
     text: dict[str, Any] | Unset = UNSET
-    reasoning: dict[str, Any] | None | Unset = UNSET
+    reasoning: dict[str, Any] | Unset | None = UNSET
     store: bool | Unset = UNSET
-    user: str | None | Unset = UNSET
+    user: str | Unset | None = UNSET
 
 
 class ResponseDeleted(Struct):
diff --git a/src/plyngent/lmproto/openai_compatible/client.py b/src/plyngent/lmproto/openai_compatible/client.py
index 328e31a..d7e6dc3 100644
--- a/src/plyngent/lmproto/openai_compatible/client.py
+++ b/src/plyngent/lmproto/openai_compatible/client.py
@@ -59,7 +59,7 @@ async def read_response_body(resp: object) -> bytes | str | None:
     return None
 
 
-def sse_data_payload(line: bytes) -> bytes | None | Literal[False]:
+def sse_data_payload(line: bytes) -> bytes | Literal[False] | None:
     """Parse one SSE line.
 
     Returns:
diff --git a/src/plyngent/lmproto/openai_compatible/model.py b/src/plyngent/lmproto/openai_compatible/model.py
index 568c22b..72bce1f 100644
--- a/src/plyngent/lmproto/openai_compatible/model.py
+++ b/src/plyngent/lmproto/openai_compatible/model.py
@@ -67,7 +67,7 @@ type AnyAssistantToolCall = AssistantFunctionToolCall | AssistantCustomToolCall
 
 class AssistantChatMessage(Struct, tag_field="role", tag="assistant"):
     # APIs often return content=null when tool_calls are present.
-    content: str | None | Unset = UNSET
+    content: str | Unset | None = UNSET
     name: str | Unset = UNSET
     audio: IDObject | Unset = UNSET
     refusal: str | Unset = UNSET
@@ -237,8 +237,8 @@ class StreamToolCallDelta(Struct):
 class DeltaMessage(Struct):
     role: RoleAssistant | Unset = UNSET
     # Providers often send content=null / reasoning_content=null on partial chunks.
-    content: str | None | Unset = UNSET
-    reasoning_content: str | None | Unset = UNSET
+    content: str | Unset | None = UNSET
+    reasoning_content: str | Unset | None = UNSET
     # True when reasoning_content is the FULL chain-of-thought (e.g. DeepSeek's
     # ``response.reasoning_text.done``), replacing any streamed fragments.
     reasoning_full: bool | Unset = UNSET
@@ -249,8 +249,8 @@ class ChunkChoice(Struct):
     index: int
     delta: DeltaMessage
     # APIs often send logprobs=null on stream choices.
-    logprobs: dict[str, Any] | None | Unset = UNSET
-    finish_reason: FinishReason | None | Unset = UNSET
+    logprobs: dict[str, Any] | Unset | None = UNSET
+    finish_reason: FinishReason | Unset | None = UNSET
 
 
 class ChatCompletionChunk(Struct):
@@ -260,7 +260,7 @@ class ChatCompletionChunk(Struct):
     model: str
     choices: list[ChunkChoice]
     # Final usage chunk may omit or null usage depending on provider.
-    usage: dict[str, Any] | None | Unset = UNSET
+    usage: dict[str, Any] | Unset | None = UNSET
 
 
 class ModelObject(Struct):