diff --git a/torax/_src/config/numerics.py b/torax/_src/config/numerics.py
index dc998bb4c..6dc45b103 100644
--- a/torax/_src/config/numerics.py
+++ b/torax/_src/config/numerics.py
@@ -40,7 +40,6 @@ class DynamicNumerics:
   resistivity_multiplier: array_typing.ScalarFloat
   adaptive_T_source_prefactor: float
   adaptive_n_source_prefactor: float
-  calcphibdot: bool
 
 
 @chex.dataclass(frozen=True)
@@ -54,6 +53,7 @@ class StaticNumerics:
   evolve_current: bool
   evolve_density: bool
   adaptive_dt: bool
+  calcphibdot: bool
 
 
 class Numerics(torax_pydantic.BaseModelFrozen):
@@ -145,7 +145,6 @@ def build_dynamic_params(
         chi_timestep_prefactor=self.chi_timestep_prefactor,
         fixed_dt=self.fixed_dt,
         dt_reduction_factor=self.dt_reduction_factor,
-        calcphibdot=self.calcphibdot,
         resistivity_multiplier=self.resistivity_multiplier.get_value(t),
         adaptive_T_source_prefactor=self.adaptive_T_source_prefactor,
         adaptive_n_source_prefactor=self.adaptive_n_source_prefactor,
@@ -159,4 +158,5 @@ def build_static_params(self) -> StaticNumerics:
         evolve_current=self.evolve_current,
         evolve_density=self.evolve_density,
         adaptive_dt=self.adaptive_dt,
+        calcphibdot=self.calcphibdot,
     )
diff --git a/torax/_src/orchestration/step_function.py b/torax/_src/orchestration/step_function.py
index 74c79acc4..973313480 100644
--- a/torax/_src/orchestration/step_function.py
+++ b/torax/_src/orchestration/step_function.py
@@ -200,6 +200,7 @@ def __call__(
       ) = _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
           input_state.t,
           dt_crash,
+          self._static_runtime_params_slice,
           self._dynamic_runtime_params_slice_provider,
           geo_t,
           self._geometry_provider,
@@ -239,6 +240,7 @@ def __call__(
         _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
             input_state.t,
             dt,
+            self._static_runtime_params_slice,
             self._dynamic_runtime_params_slice_provider,
             geo_t,
             self._geometry_provider,
@@ -544,6 +546,7 @@ def body_fun(
       ) = _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
           input_state.t,
           dt,
+          self._static_runtime_params_slice,
           self._dynamic_runtime_params_slice_provider,
           geo_t,
           self._geometry_provider,
@@ -852,6 +855,7 @@ def _calculate_total_transport_coeffs(
 def _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
     t: jax.Array,
     dt: jax.Array,
+    static_runtime_params_slice: runtime_params_slice.StaticRuntimeParamsSlice,
     dynamic_runtime_params_slice_provider: build_runtime_params.DynamicRuntimeParamsSliceProvider,
     geo_t: geometry.Geometry,
     geometry_provider: geometry_provider_lib.GeometryProvider,
@@ -865,6 +869,7 @@ def _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
   Args:
     t: Time at which the simulation is currently at.
     dt: Time step duration.
+    static_runtime_params_slice: Static runtime parameters.
     dynamic_runtime_params_slice_provider: Object that returns a set of runtime
       parameters which may change from time step to time step or simulation run
       to run. If these runtime parameters change, it does NOT trigger a JAX
@@ -886,7 +891,7 @@ def _get_geo_and_dynamic_runtime_params_at_t_plus_dt_and_phibdot(
           geometry_provider=geometry_provider,
       )
   )
-  if dynamic_runtime_params_slice_t_plus_dt.numerics.calcphibdot:
+  if static_runtime_params_slice.numerics.calcphibdot:
     geo_t, geo_t_plus_dt = geometry.update_geometries_with_Phibdot(
         dt=dt,
         geo_t=geo_t,