diff --git a/python/sdist/amici/jax/petab.py b/python/sdist/amici/jax/petab.py
index 7e68c5c34d..6a7da4b42f 100644
--- a/python/sdist/amici/jax/petab.py
+++ b/python/sdist/amici/jax/petab.py
@@ -495,7 +495,7 @@ def run_simulation(
             simulation_condition[0], p
         )
         return self.model.simulate_condition(
-            p=eqx.debug.backward_nan(p),
+            p=p,
             ts_dyn=jax.lax.stop_gradient(jnp.array(ts_dyn)),
             ts_posteq=jax.lax.stop_gradient(jnp.array(ts_posteq)),
             my=jax.lax.stop_gradient(jnp.array(my)),