diff --git a/src/openai/lib/streaming/responses/_responses.py b/src/openai/lib/streaming/responses/_responses.py
index 6975a9260d..2c803889c4 100644
--- a/src/openai/lib/streaming/responses/_responses.py
+++ b/src/openai/lib/streaming/responses/_responses.py
@@ -328,7 +328,9 @@ def accumulate_event(self, event: RawResponseStreamEvent) -> ParsedResponseSnaps
             return self._create_initial_response(event)
 
         if event.type == "response.output_item.added":
-            if event.item.type == "function_call":
+            if event.item is None:
+                pass
+            elif event.item.type == "function_call":
                 snapshot.output.append(
                     construct_type_unchecked(
                         type_=cast(Any, ParsedResponseFunctionToolCall), value=event.item.to_dict()
diff --git a/src/openai/types/beta/beta_response_output_item_added_event.py b/src/openai/types/beta/beta_response_output_item_added_event.py
index 4e12b9d3d0..cddf411acb 100644
--- a/src/openai/types/beta/beta_response_output_item_added_event.py
+++ b/src/openai/types/beta/beta_response_output_item_added_event.py
@@ -19,7 +19,7 @@ class Agent(BaseModel):
 class BetaResponseOutputItemAddedEvent(BaseModel):
     """Emitted when a new output item is added."""
 
-    item: BetaResponseOutputItem
+    item: Optional[BetaResponseOutputItem] = None
     """The output item that was added.
 
     For reasoning items, `encrypted_content` may be incomplete while the item is in
diff --git a/src/openai/types/responses/response.py b/src/openai/types/responses/response.py
index 762080dc0f..39c0590de8 100644
--- a/src/openai/types/responses/response.py
+++ b/src/openai/types/responses/response.py
@@ -486,7 +486,7 @@ def output_text(self) -> str:
         for output in self.output:
             if output.type == "message":
                 for content in output.content:
-                    if content.type == "output_text":
+                    if content.type == "output_text" and content.text is not None:
                         texts.append(content.text)
 
         return "".join(texts)
diff --git a/src/openai/types/responses/response_output_item_added_event.py b/src/openai/types/responses/response_output_item_added_event.py
index 36ac0e2245..a8754b95d8 100644
--- a/src/openai/types/responses/response_output_item_added_event.py
+++ b/src/openai/types/responses/response_output_item_added_event.py
@@ -1,5 +1,6 @@
 # File generated from our OpenAPI spec by Castiron. See CONTRIBUTING.md for details.
 
+from typing import Optional
 from typing_extensions import Literal
 
 from ..._models import BaseModel
@@ -11,7 +12,7 @@
 class ResponseOutputItemAddedEvent(BaseModel):
     """Emitted when a new output item is added."""
 
-    item: ResponseOutputItem
+    item: Optional[ResponseOutputItem] = None
     """The output item that was added.
 
     For reasoning items, `encrypted_content` may be incomplete while the item is in