diff --git a/evoprompt/models.py b/evoprompt/models.py
index d2f45dc3a9ae89a89fa84007427037b18f67105d..0d11a8618fe5166c000b9fceb0929b720e5988c6 100644
--- a/evoprompt/models.py
+++ b/evoprompt/models.py
@@ -119,7 +119,7 @@ class Llama(LLMModel):
         prompt_suffix: str = "",
         chat: bool | None = None,
         stop: str = None,
-        max_tokens: int = 200,
+        max_tokens: int = None,
         history: dict = None,
         **kwargs: Any,
     ) -> tuple[str, ModelUsage]:
@@ -252,7 +252,7 @@ class OpenAI(LLMModel):
         prompt_suffix: str = "",
         chat: bool | None = None,
         stop: str = "</prompt>",
-        max_tokens: int = 200,
+        max_tokens: int = None,
         **kwargs: Any,
     ) -> tuple[str, ModelUsage]:
         if chat is None: