diff --git a/src/openai/_streaming.py b/src/openai/_streaming.py
index 45c13cc11d..bdfdb8b5e6 100644
--- a/src/openai/_streaming.py
+++ b/src/openai/_streaming.py
@@ -63,11 +63,9 @@ def __stream__(self) -> Iterator[_T]:
                 if sse.data.startswith("[DONE]"):
                     break
 
-                # we have to special case the Assistants `thread.` events since we won't have an "event" key in the data
-                if sse.event and sse.event.startswith("thread."):
+                if sse.event == "error":
                     data = sse.json()
-
-                    if sse.event == "error" and is_mapping(data) and data.get("error"):
+                    if is_mapping(data) and data.get("error"):
                         message = None
                         error = data.get("error")
                         if is_mapping(error):
@@ -81,6 +79,10 @@ def __stream__(self) -> Iterator[_T]:
                             body=data["error"],
                         )
 
+                # we have to special case the Assistants `thread.` events since we won't have an "event" key in the data
+                if sse.event and sse.event.startswith("thread."):
+                    data = sse.json()
+
                     yield process_data(data={"data": data, "event": sse.event}, cast_to=cast_to, response=response)
                 else:
                     data = sse.json()
@@ -173,11 +175,9 @@ async def __stream__(self) -> AsyncIterator[_T]:
                 if sse.data.startswith("[DONE]"):
                     break
 
-                # we have to special case the Assistants `thread.` events since we won't have an "event" key in the data
-                if sse.event and sse.event.startswith("thread."):
+                if sse.event == "error":
                     data = sse.json()
-
-                    if sse.event == "error" and is_mapping(data) and data.get("error"):
+                    if is_mapping(data) and data.get("error"):
                         message = None
                         error = data.get("error")
                         if is_mapping(error):
@@ -191,6 +191,10 @@ async def __stream__(self) -> AsyncIterator[_T]:
                             body=data["error"],
                         )
 
+                # we have to special case the Assistants `thread.` events since we won't have an "event" key in the data
+                if sse.event and sse.event.startswith("thread."):
+                    data = sse.json()
+
                     yield process_data(data={"data": data, "event": sse.event}, cast_to=cast_to, response=response)
                 else:
                     data = sse.json()