diff --git a/docutranslate/translator/ai_translator/base.py b/docutranslate/translator/ai_translator/base.py
index 770463e..bd674b0 100644
--- a/docutranslate/translator/ai_translator/base.py
+++ b/docutranslate/translator/ai_translator/base.py
@@ -45,7 +45,6 @@ class AiTranslator(Translator[T]):
                     baseurl=config.base_url,
                     key=config.api_key,
                     model_id=config.model_id,
-                    system_prompt=None,
                     temperature=config.temperature,
                     thinking=config.thinking,
                     max_concurrent=config.concurrent,