diff --git a/env.example b/env.example
index 5646874e..90bd5a67 100644
--- a/env.example
+++ b/env.example
@@ -149,7 +149,9 @@ LLM_BINDING_API_KEY=your_api_key
 ### OpenAI Specific Parameters
 # OPENAI_LLM_TEMPERATURE=1.0
 # OPENAI_LLM_REASONING_EFFORT=low
-### Set the maximum number of completion tokens if your LLM generates repetitive or unconstrained output
+### For models like Qwen3 with fewer than 32B param, it is recommended to set the presence penalty to 1.5
+# OPENAI_LLM_PRESENCE_PENALTY=1.5
+### If the presence penalty still can not stop the model from generates repetitive or unconstrained output
 # OPENAI_LLM_MAX_COMPLETION_TOKENS=16384
 ### use the following command to see all support options for openai and azure_openai
 ### lightrag-server --llm-binding openai --help