diff --git a/vllm/engine/arg_utils.py b/vllm/engine/arg_utils.py
index a5b155024b73a..e3b8a18ccdfef 100644
--- a/vllm/engine/arg_utils.py
+++ b/vllm/engine/arg_utils.py
@@ -455,7 +455,7 @@ class EngineArgs:
             title="ModelConfig",
             description=ModelConfig.__doc__,
         )
-        if 'serve' not in sys.argv[1:] and '--help' not in sys.argv[1:]:
+        if not ('serve' in sys.argv[1:] and '--help' in sys.argv[1:]):
             model_group.add_argument("--model", **model_kwargs["model"])
         model_group.add_argument("--task", **model_kwargs["task"])
         model_group.add_argument("--tokenizer", **model_kwargs["tokenizer"])