diff --git a/src/lerobot/optim/optimizers.py b/src/lerobot/optim/optimizers.py
index 3d9ec6b98..6ec38491b 100644
--- a/src/lerobot/optim/optimizers.py
+++ b/src/lerobot/optim/optimizers.py
@@ -105,6 +105,7 @@ class AdamWConfig(OptimizerConfig):
     weight_decay: float = 1e-2
     grad_clip_norm: float = 10.0
     foreach: bool | None = None
+    fused: bool | None = None
 
     def build(self, params: OptimizerParams) -> torch.optim.Optimizer:
         kwargs = asdict(self)
diff --git a/src/lerobot/policies/pi05/configuration_pi05.py b/src/lerobot/policies/pi05/configuration_pi05.py
index d15cc0ee8..192fce448 100644
--- a/src/lerobot/policies/pi05/configuration_pi05.py
+++ b/src/lerobot/policies/pi05/configuration_pi05.py
@@ -94,6 +94,7 @@ class PI05Config(PreTrainedConfig):
     optimizer_weight_decay: float = 0.01
     optimizer_grad_clip_norm: float = 1.0
     optimizer_foreach: bool | None = False
+    optimizer_fused: bool | None = True
 
     # Scheduler settings: see openpi `CosineDecaySchedule`
     # Note: These will auto-scale if --steps < scheduler_decay_steps
@@ -154,6 +155,7 @@ class PI05Config(PreTrainedConfig):
             weight_decay=self.optimizer_weight_decay,
             grad_clip_norm=self.optimizer_grad_clip_norm,
             foreach=self.optimizer_foreach,
+            fused=self.optimizer_fused,
         )
 
     def get_scheduler_preset(self):