diff --git a/src/lerobot/policies/xvla/configuration_florence2.py b/src/lerobot/policies/xvla/configuration_florence2.py
index 35c006ee0..77f1b3a1d 100644
--- a/src/lerobot/policies/xvla/configuration_florence2.py
+++ b/src/lerobot/policies/xvla/configuration_florence2.py
@@ -276,6 +276,8 @@ class Florence2LanguageConfig(PretrainedConfig):
         )
 
         # ensure backward compatibility for BART CNN models
+        if not hasattr(self, "forced_bos_token_id"):
+            self.forced_bos_token_id = None
         if self.forced_bos_token_id is None and kwargs.get("force_bos_token_to_be_generated", False):
             self.forced_bos_token_id = self.bos_token_id
             warnings.warn(