diff --git a/benchmarks/benchmark_serving.py b/benchmarks/benchmark_serving.py
index 3ace910a6cac6..a407a263120bb 100644
--- a/benchmarks/benchmark_serving.py
+++ b/benchmarks/benchmark_serving.py
@@ -626,9 +626,9 @@ def main(args: argparse.Namespace):
                 prefix_len=args.sonnet_prefix_len,
                 tokenizer=tokenizer,
             )
-            input_requests = [(prompt, prompt_len, output_len)
+            input_requests = [(prompt, prompt_len, output_len, None)
                               for prompt, prompt_formatted, prompt_len,
-                              output_len in input_requests]
+                              output_len, _ in input_requests]
         else:
             assert (
                 tokenizer.chat_template or tokenizer.default_chat_template
@@ -641,9 +641,9 @@ def main(args: argparse.Namespace):
                 prefix_len=args.sonnet_prefix_len,
                 tokenizer=tokenizer,
             )
-            input_requests = [(prompt_formatted, prompt_len, output_len)
+            input_requests = [(prompt_formatted, prompt_len, output_len, None)
                               for prompt, prompt_formatted, prompt_len,
-                              output_len in input_requests]
+                              output_len, _ in input_requests]
 
     elif args.dataset_name == "hf":
         input_requests = sample_hf_requests(
@@ -963,4 +963,4 @@ def main(args: argparse.Namespace):
     )
 
     args = parser.parse_args()
-    main(args)
+    main(args)
\ No newline at end of file