diff --git a/src/jimgw/single_event/likelihood.py b/src/jimgw/single_event/likelihood.py
index 00e6ce6b..acb431f5 100644
--- a/src/jimgw/single_event/likelihood.py
+++ b/src/jimgw/single_event/likelihood.py
@@ -575,18 +575,34 @@ def y(x):
         )
 
         key = jax.random.PRNGKey(0)
-        initial_position = []
-        for _ in range(popsize):
-            flag = True
-            while flag:
-                key = jax.random.split(key)[1]
-                guess = prior.sample(key, 1)
-                for transform in sample_transforms:
-                    guess = transform.forward(guess)
-                guess = jnp.array([i for i in guess.values()]).T[0]
-                flag = not jnp.all(jnp.isfinite(guess))
-            initial_position.append(guess)
-        initial_position = jnp.array(initial_position)
+
+        initial_position = jnp.zeros((popsize, prior.n_dim)) + jnp.nan
+        while not jax.tree.reduce(
+            jnp.logical_and, jax.tree.map(lambda x: jnp.isfinite(x), initial_position)
+        ).all():
+            non_finite_index = jnp.any(
+                ~jax.tree.reduce(
+                    jnp.logical_and,
+                    jax.tree.map(lambda x: jnp.isfinite(x), initial_position),
+                ),
+                axis=1,
+            )
+
+            key, subkey = jax.random.split(key)
+            guess = prior.sample(subkey, popsize)
+            for transform in sample_transforms:
+                guess = jax.vmap(transform.forward)(guess)
+            guess = jnp.array(
+                jax.tree.leaves({key: guess[key] for key in parameter_names})
+            ).T
+            finite_guess = jnp.where(
+                jnp.all(jax.tree.map(lambda x: jnp.isfinite(x), guess), axis=1)
+            )[0]
+            common_length = min(len(finite_guess), len(non_finite_index))
+            initial_position = initial_position.at[
+                non_finite_index[:common_length]
+            ].set(guess[:common_length])
+
         rng_key, optimized_positions, summary = optimizer.optimize(
             jax.random.PRNGKey(12094), y, initial_position
         )