diff --git a/src/nanotron/models/llama.py b/src/nanotron/models/llama.py
index 9e31bd39..3206bce0 100644
--- a/src/nanotron/models/llama.py
+++ b/src/nanotron/models/llama.py
@@ -168,7 +168,8 @@ def __init__(
             bias=False,
             async_communication=tp_linear_async_communication and tp_mode is TensorParallelLinearMode.REDUCE_SCATTER,
         )
-        do_compile = True
+        # do_compile = True
+        do_compile = False
         # self.split_silu_mul = torch.compile(GLUActivation(config.hidden_act))
         self.split_silu_mul = GLUActivation(config.hidden_act)
         if do_compile:
diff --git a/src/nanotron/serialize/main.py b/src/nanotron/serialize/main.py
index 5a6b797e..816f044d 100644
--- a/src/nanotron/serialize/main.py
+++ b/src/nanotron/serialize/main.py
@@ -63,7 +63,7 @@ def save(
     sanity_checks: bool = True,
 ) -> None:
     assert isinstance(training_metadata, TrainingMetadata)
-    assert isinstance(valid_metadata, TrainingMetadata)
+    assert (valid_metadata is None) or isinstance(valid_metadata, TrainingMetadata)
 
     try:
         if should_save_config:
diff --git a/src/nanotron/serialize/metadata.py b/src/nanotron/serialize/metadata.py
index 35204899..6c55d5e6 100644
--- a/src/nanotron/serialize/metadata.py
+++ b/src/nanotron/serialize/metadata.py
@@ -64,7 +64,7 @@ class CheckpointMetadata:
     tp: int
     dp: int
     train_meta: TrainingMetadata
-    valid_meta: TrainingMetadata
+    valid_meta: Optional[TrainingMetadata]
 
 
 @dataclasses.dataclass
@@ -130,7 +130,7 @@ def save_meta(parallel_context: ParallelContext,
               training_metadata: TrainingMetadata,
               valid_metadata: TrainingMetadata):
     assert isinstance(training_metadata, TrainingMetadata)
-    assert isinstance(valid_metadata, TrainingMetadata)
+    assert (valid_metadata is None) or isinstance(valid_metadata, TrainingMetadata)
 
     if dist.get_rank(parallel_context.world_pg) != 0:
         return
diff --git a/src/nanotron/trainer.py b/src/nanotron/trainer.py
index da8d1bd4..65569e7c 100644
--- a/src/nanotron/trainer.py
+++ b/src/nanotron/trainer.py
@@ -229,7 +229,7 @@ def __init__(
                 parallel_context=self.parallel_context, root_folder=self.init_checkpoint_path
             )
             assert isinstance(checkpoint_metadata.train_meta, TrainingMetadata)
-            assert isinstance(checkpoint_metadata.valid_meta, TrainingMetadata)
+            assert (checkpoint_metadata.valid_meta is None) or isinstance(checkpoint_metadata.valid_meta, TrainingMetadata)
 
             log_rank(str(checkpoint_metadata), logger=logger, level=logging.INFO, rank=0)
             self.metadata: TrainingMetadata = checkpoint_metadata.train_meta
@@ -688,7 +688,6 @@ def train_step_logs(
 
         if dist.get_rank(self.parallel_context.world_pg) in self.logger_ranks:
             assert self.loggerwriter is not None, "loggerwriter should be defined on logger ranks"
-
             lr = self.lr_scheduler.get_last_lr()[0]
 
             log_entries = [