diff --git a/flax/nnx/nn/normalization.py b/flax/nnx/nn/normalization.py
index e06ab9fcd..1766da5b0 100644
--- a/flax/nnx/nn/normalization.py
+++ b/flax/nnx/nn/normalization.py
@@ -290,7 +290,7 @@ def __init__(
     self,
     num_features: int,
     *,
-    use_running_average: bool | None = False,
+    use_running_average: bool | None = None,
     axis: int = -1,
     momentum: float = 0.99,
     epsilon: float = 1e-5,
diff --git a/flax/nnx/nn/stochastic.py b/flax/nnx/nn/stochastic.py
index 6d03e7353..4dcc78925 100644
--- a/flax/nnx/nn/stochastic.py
+++ b/flax/nnx/nn/stochastic.py
@@ -73,7 +73,7 @@ def __init__(
     rate: float,
     *,
     broadcast_dims: Sequence[int] = (),
-    deterministic: bool | None = False,
+    deterministic: bool | None = None,
     rng_collection: str = 'dropout',
     rngs: rnglib.Rngs | rnglib.RngStream | None = None,
   ):