diff --git a/src/transformers/trainer.py b/src/transformers/trainer.py
index 87a0e2b94a65..94c3a8620cbb 100755
--- a/src/transformers/trainer.py
+++ b/src/transformers/trainer.py
@@ -783,15 +783,17 @@ def __init__(
         # returned to 0 every time flos need to be logged
         self.current_flos = 0
         self.hp_search_backend = None
-        if _is_peft_model(self.model) and self.args.label_names is None:
-            logger.warning(
-                f"No label_names provided for model class `{self.model.__class__.__name__}`."
-                " Since `PeftModel` hides base models input arguments, if label_names is not given, label_names can't be set automatically within `Trainer`."
-                " Note that empty label_names list will be used instead."
-            )
-        default_label_names = find_labels(self.model.__class__)
+
+        model_to_inspect = self.model
+        if _is_peft_model(self.model):
+            if hasattr(self.model, "get_base_model"):
+                model_to_inspect = self.model.get_base_model()
+            else:
+                # PeftMixedModel do not provide a `get_base_model` method
+                model_to_inspect = self.model.base_model.model
+        default_label_names = find_labels(model_to_inspect.__class__)
         self.label_names = default_label_names if self.args.label_names is None else self.args.label_names
-        self.can_return_loss = can_return_loss(self.model.__class__)
+        self.can_return_loss = can_return_loss(model_to_inspect.__class__)
         self.control = self.callback_handler.on_init_end(self.args, self.state, self.control)
 
         # Internal variables to help with automatic batch size reduction