diff --git a/dynamax/slds/mixture_kalman_filter_demo.py b/dynamax/slds/mixture_kalman_filter_demo.py
index 9302b913..18c0d7aa 100644
--- a/dynamax/slds/mixture_kalman_filter_demo.py
+++ b/dynamax/slds/mixture_kalman_filter_demo.py
@@ -3,11 +3,12 @@
 
 # Author: Gerardo Durán-Martín (@gerdm)
 
+from dataclasses import dataclass
 import jax
-import jax.numpy as jnp
 from jax import random
+import jax.numpy as jnp
 from jax.scipy.special import logit
-from dataclasses import dataclass
+from jaxtyping import Array, Float
 
 
 @dataclass
@@ -24,12 +25,12 @@ class RBPFParamsDiscrete:
         noise1_next ~ N(0, Q)
         noise2_next ~ N(0, R)
     """
-    A: jnp.array
-    B: jnp.array
-    C: jnp.array
-    Q: jnp.array
-    R: jnp.array
-    transition_matrix: jnp.array
+    A: Float[Array, "dim_hidden dim_hidden"]
+    B: Float[Array, "dim_hidden dim_control"]
+    C: Float[Array, "dim_emission dim_hidden"]
+    Q: Float[Array, "dim_hidden dim_hidden"]
+    R: Float[Array, "dim_emission dim_emission"]
+    transition_matrix: Float[Array, "dim_control dim_control"]
 
 
 def draw_state(val, key, params):
@@ -42,7 +43,7 @@ def draw_state(val, key, params):
     ----------
     val: tuple (int, jnp.array)
         (latent value of system, state value of system).
-    params: PRBPFParamsDiscrete
+    params: RBPFParamsDiscrete
     key: PRNGKey
     """
     latent_old, state_old = val
@@ -158,4 +159,4 @@ def rbpf_optimal(current_config, xt, params, nparticles=100):
     
     weights_t = jnp.ones(nparticles) / nparticles
     
-    return (key_next, mu_t, Sigma_t, weights_t, st), (mu_t, Sigma_t, weights_t, st, proposal_samp)
\ No newline at end of file
+    return (key_next, mu_t, Sigma_t, weights_t, st), (mu_t, Sigma_t, weights_t, st, proposal_samp)