diff --git a/api/core/app/apps/completion/generate_response_converter.py b/api/core/app/apps/completion/generate_response_converter.py
index d7e9ebdf24..a4f574642d 100644
--- a/api/core/app/apps/completion/generate_response_converter.py
+++ b/api/core/app/apps/completion/generate_response_converter.py
@@ -112,7 +112,7 @@ class CompletionAppGenerateResponseConverter(AppGenerateResponseConverter):
                     metadata = {}
                 sub_stream_response_dict["metadata"] = cls._get_simple_metadata(metadata)
                 response_chunk.update(sub_stream_response_dict)
-            if isinstance(sub_stream_response, ErrorStreamResponse):
+            elif isinstance(sub_stream_response, ErrorStreamResponse):
                 data = cls._error_to_stream_response(sub_stream_response.err)
                 response_chunk.update(data)
             else: