diff --git a/lerobot/common/datasets/abstract.py b/lerobot/common/datasets/abstract.py
index 8d17cd78..7b8a8423 100644
--- a/lerobot/common/datasets/abstract.py
+++ b/lerobot/common/datasets/abstract.py
@@ -21,7 +21,7 @@ class AbstractExperienceReplay(TensorDictReplayBuffer):
     def __init__(
         self,
         dataset_id: str,
-        version: str | None = "v1.0",
+        version: str | None,
         batch_size: int = None,
         *,
         shuffle: bool = True,
diff --git a/lerobot/common/datasets/simxarm.py b/lerobot/common/datasets/simxarm.py
index af006f76..3b1c75be 100644
--- a/lerobot/common/datasets/simxarm.py
+++ b/lerobot/common/datasets/simxarm.py
@@ -40,7 +40,7 @@ class SimxarmExperienceReplay(AbstractExperienceReplay):
     def __init__(
         self,
         dataset_id: str,
-        version: str | None = None,
+        version: str | None = "v1.0",
         batch_size: int = None,
         *,
         shuffle: bool = True,