diff --git a/src/lighteval/models/base_model.py b/src/lighteval/models/base_model.py
index aed6ca8e7..6b67e4c0c 100644
--- a/src/lighteval/models/base_model.py
+++ b/src/lighteval/models/base_model.py
@@ -626,7 +626,7 @@ def _loglikelihood_tokens(
         return dataset.get_original_order(res)
 
     def prepare_batch(
-        self, batch: list[str], padding_length: int, max_context: Optional[int] = None, single_token: bool = False
+        self, batch: list[Request], padding_length: int, max_context: Optional[int] = None, single_token: bool = False
     ):
         """Tokenize a batch of inputs and return also the length, truncations and padding"""
         if single_token: