diff --git a/tests/test_model.py b/tests/test_model.py
index 096a2ba..53dddeb 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -3,7 +3,7 @@
 
 import numpy as np
 import pytest
-from astropy import time, units
+from astropy import coordinates, time, units
 
 from zodipy import Model, grid_number_density, model_registry
 
@@ -60,12 +60,16 @@ def test_get_parameters() -> None:
 def test_update_model() -> None:
     """Tests that the model can be updated."""
     model = Model(20 * units.micron, name="dirbe")
-
+    obstime = time.Time("2021-01-01T00:00:00")
+    skycoord = coordinates.SkyCoord(20, 30, unit=units.deg, obstime=obstime)
+    emission_before = model.evaluate(skycoord)
     parameters = model.get_parameters()
     comp = random.choice(list(parameters["comps"].keys()))
     parameter = random.choice(list(parameters["comps"][comp]))
     parameters["comps"][comp][parameter] = random.random()
     model.update_parameters(parameters)
+    emission_after = model.evaluate(skycoord)
+    assert not np.allclose(emission_before, emission_after)
 
 
 def test_get_model_raises_error() -> None:
diff --git a/zodipy/model.py b/zodipy/model.py
index 94ff412..15bed65 100644
--- a/zodipy/model.py
+++ b/zodipy/model.py
@@ -88,16 +88,10 @@ def __init__(
             normalized_weights = weights / integrate.trapezoid(weights, x)
         else:
             normalized_weights = None
-        self._b_nu_table = tabulate_blackbody_emission(x, normalized_weights)
 
-        # We interpolate the spectrally dependant zodiacal light parameters over the provided
-        # bandpass or delta frequency/wavelength.
-        interp_and_unpack_func = get_model_interp_func(self._ipd_model)
-        self._interped_comp_params, self._interped_shared_params = interp_and_unpack_func(
-            x, normalized_weights, self._ipd_model
-        )
-
-        self._ephemeris = ephemeris
+        self._x = x
+        self._normalized_weights = normalized_weights
+        self._b_nu_table = tabulate_blackbody_emission(self._x, self._normalized_weights)
 
         quad_points, quad_weights = np.polynomial.legendre.leggauss(gauss_quad_degree)
         self._integrate_leggauss = functools.partial(
@@ -106,14 +100,14 @@ def __init__(
             weights=quad_weights,
         )
 
-        # Build partial functions to be evaluated when simulating the zodiacal light. These partials
-        # are pre-populated functions that contains all non line-of-sight related parameters.
-        self._number_density_partials = get_partial_number_density_func(comps=self._ipd_model.comps)
-        self._shared_brightness_partial = functools.partial(
-            self._ipd_model.brightness_at_step_callable,
-            bp_interpolation_table=self._b_nu_table,
-            **self._interped_shared_params,
-        )
+        self._ephemeris = ephemeris
+
+        # Make mypy happy by declaring types of to-be initialized attributes.
+        self._number_density_partials: dict[ComponentLabel, functools.partial]
+        self._interped_comp_params: dict[ComponentLabel, dict]
+        self._interped_shared_params: dict
+
+        self._init_ipd_model_partials()
 
     def evaluate(
         self,
@@ -178,6 +172,7 @@ def evaluate(
 
         number_density_partials = self._number_density_partials
         shared_brightness_partial = self._shared_brightness_partial
+
         dist_coords_to_cores = skycoord.size > nprocesses and nprocesses > 1
         if instantaneous or not dist_coords_to_cores:
             # Populate the instantaneous Earth and observer position in the partial functions.
@@ -276,6 +271,26 @@ def evaluate(
         emission <<= units.MJy / units.sr
         return emission if return_comps else emission.sum(axis=0)
 
+    def _init_ipd_model_partials(self) -> None:
+        """Initialize the partial functions for the interplanetary dust model.
+
+        The spectrally dependant model parameters are interpolated over the provided bandpass or
+        delta frequency/wavelength. The partial functions are pre-populated functions that contains
+        all non line-of-sight related parameters.
+        """
+        interp_and_unpack_func = get_model_interp_func(self._ipd_model)
+        dicts = interp_and_unpack_func(self._x, self._normalized_weights, self._ipd_model)
+        self._interped_comp_params = dicts[0]
+        self._interped_shared_params = dicts[1]
+
+        self._shared_brightness_partial = functools.partial(
+            self._ipd_model.brightness_at_step_callable,
+            bp_interpolation_table=self._b_nu_table,
+            **self._interped_shared_params,
+        )
+
+        self._number_density_partials = get_partial_number_density_func(comps=self._ipd_model.comps)
+
     def get_parameters(self) -> dict:
         """Return a dictionary containing the interplanetary dust model parameters.
 
@@ -294,7 +309,8 @@ def update_parameters(self, parameters: dict) -> None:
         Args:
             parameters: Dictionary of parameters to update. The keys must be the names
                 of the parameters as defined in the model. To get the parameters dict
-                of an existing model, use `Zodipy("dirbe").get_parameters()`.
+                of an existing model, use the`get_parameters` method of an initialized
+                `zodipy.Model`.
         """
         _dict = parameters.copy()
         _dict["comps"] = {}
@@ -308,6 +324,7 @@ def update_parameters(self, parameters: dict) -> None:
                 _dict[key] = {ComponentLabel(k): v for k, v in value.items()}
 
         self._ipd_model = self._ipd_model.__class__(**_dict)
+        self._init_ipd_model_partials()
 
 
 def validate_user_input(skycoord: coords.SkyCoord, obspos: units.Quantity | str) -> time.Time: