diff --git a/numpyro_sts/base.py b/numpyro_sts/base.py
index 88c5945..b71496e 100644
--- a/numpyro_sts/base.py
+++ b/numpyro_sts/base.py
@@ -22,7 +22,9 @@ def _loc_transition(state, offset, matrix) -> jnp.ndarray:
     return offset + (matrix @ state[..., None]).reshape(state.shape)
 
 
-def _sample_shocks(key: PRNGKey, event_shape: Tuple[int, ...], batch_shape: Tuple[int, ...], selector: jnp.ndarray) -> jnp.ndarray:
+def _sample_shocks(
+    key: PRNGKey, event_shape: Tuple[int, ...], batch_shape: Tuple[int, ...], selector: jnp.ndarray
+) -> jnp.ndarray:
     shock_shape = event_shape[:-1] + selector.shape[-1:]
 
     flat_shape = () if not batch_shape else (reduce(lambda u, v: u * v, batch_shape),)
diff --git a/numpyro_sts/periodic/cyclical.py b/numpyro_sts/periodic/cyclical.py
index ed705e1..67d736a 100644
--- a/numpyro_sts/periodic/cyclical.py
+++ b/numpyro_sts/periodic/cyclical.py
@@ -14,7 +14,7 @@ class Cyclical(LinearTimeseries):
     """
 
     def __init__(self, n: int, periodicity: ArrayLike, std: ArrayLike, initial_value: ArrayLike, **kwargs):
-        lamda, = cast_to_tensor(periodicity)
+        (lamda,) = cast_to_tensor(periodicity)
 
         cos_lamda = jnp.cos(lamda)
         sin_lamda = jnp.sin(lamda)