diff --git a/bergson/config.py b/bergson/config.py
index 4f5a0fae..9855129f 100644
--- a/bergson/config.py
+++ b/bergson/config.py
@@ -296,7 +296,11 @@ class TrainingConfig(AttributionConfig, Serializable):
     """Number of full passes over the training data."""
 
     seed: int = 42
-    """Random seed for dataset shuffling."""
+    """Random seed for training and validation randomness."""
+
+    shuffle_seed: int | None = None
+    """Random seed for shuffling the training dataset.
+    """
 
     adam_beta1: float = 0.95
     """Beta1 for AdamW optimizer."""
diff --git a/bergson/magic/cli.py b/bergson/magic/cli.py
index 37da0878..dae33800 100644
--- a/bergson/magic/cli.py
+++ b/bergson/magic/cli.py
@@ -606,8 +606,12 @@ def run_magic(run_cfg: TrainingConfig, *, score_path: str = ""):
     train_ds, train_n = setup_data_pipeline(run_cfg)
     train_ds = attach_doc_ids_if_missing(train_ds)
 
-    # Shuffle the train_ds with the seed.
-    train_ds = train_ds.shuffle(seed=run_cfg.seed)
+    # Shuffle the train_ds with the shuffle seed, defaulting to seed for
+    # backward compatibility with existing MAGIC configs.
+    shuffle_seed = (
+        run_cfg.seed if run_cfg.shuffle_seed is None else run_cfg.shuffle_seed
+    )
+    train_ds = train_ds.shuffle(seed=shuffle_seed)
 
     if isinstance(run_cfg, ValidationConfig):
         query_ds, query_n = setup_data_pipeline(run_cfg, run_cfg.query)