diff --git a/src/openai/lib/streaming/chat/_completions.py b/src/openai/lib/streaming/chat/_completions.py
index 2146091354..4623e16306 100644
--- a/src/openai/lib/streaming/chat/_completions.py
+++ b/src/openai/lib/streaming/chat/_completions.py
@@ -434,6 +434,8 @@ def _accumulate_chunk(self, chunk: ChatCompletionChunk) -> ParsedChatCompletionS
                 choice_snapshot.message.content
                 and not choice_snapshot.message.refusal
                 and is_given(self._rich_response_format)
+                # partial parsing fails on white-space
+                and choice_snapshot.message.content.strip()
             ):
                 choice_snapshot.message.parsed = from_json(
                     bytes(choice_snapshot.message.content, "utf-8"),