diff --git a/autogalaxy/imaging/model/analysis.py b/autogalaxy/imaging/model/analysis.py
index 1a2f0e46..e2ea6fc3 100644
--- a/autogalaxy/imaging/model/analysis.py
+++ b/autogalaxy/imaging/model/analysis.py
@@ -141,6 +141,9 @@ def fit_from(self, instance: af.ModelInstance) -> FitImaging:
             The fit of the galaxies to the imaging dataset, which includes the log likelihood.
         """
 
+        if self._use_jax:
+            self._register_fit_imaging_pytrees()
+
         galaxies = self.galaxies_via_instance_from(
             instance=instance,
         )
@@ -158,6 +161,48 @@ def fit_from(self, instance: af.ModelInstance) -> FitImaging:
             xp=self._xp,
         )
 
+    @staticmethod
+    def _register_fit_imaging_pytrees() -> None:
+        """Register every type reachable from a ``FitImaging`` return value
+        so ``jax.jit(fit_from)`` can flatten its output.
+
+        ``dataset``, ``adapt_images`` and ``settings`` are constants per
+        analysis — ride as aux so JAX does not recurse into them. Everything
+        else (``galaxies``, ``dataset_model`` and the autoarray wrappers they
+        carry) is dynamic per fit.
+        """
+        from autoarray.abstract_ndarray import (
+            _pytree_registered_classes,
+            register_instance_pytree,
+        )
+        from autoarray.dataset.dataset_model import DatasetModel
+        from autoconf.jax_wrapper import register_pytree_node
+        from autogalaxy.galaxy.galaxies import Galaxies
+
+        register_instance_pytree(
+            FitImaging,
+            no_flatten=("dataset", "adapt_images", "settings"),
+        )
+        register_instance_pytree(DatasetModel)
+
+        # ``Galaxies`` is a ``list`` subclass — the generic ``__dict__`` flatten
+        # in ``register_instance_pytree`` would drop the list contents. Register
+        # a custom flatten that carries the list items as dynamic children.
+        if Galaxies not in _pytree_registered_classes:
+            def _flatten_galaxies(galaxies):
+                dict_items = tuple(sorted(galaxies.__dict__.items()))
+                return tuple(galaxies), dict_items
+
+            def _unflatten_galaxies(aux, children):
+                new = Galaxies.__new__(Galaxies)
+                list.__init__(new, children)
+                for key, value in aux:
+                    setattr(new, key, value)
+                return new
+
+            register_pytree_node(Galaxies, _flatten_galaxies, _unflatten_galaxies)
+            _pytree_registered_classes.add(Galaxies)
+
     def save_attributes(self, paths: af.DirectoryPaths):
         """
         Before the non-linear search begins, this routine saves attributes of the `Analysis` object to the `files`
diff --git a/test_autogalaxy/imaging/model/test_analysis_imaging.py b/test_autogalaxy/imaging/model/test_analysis_imaging.py
index d65b64a3..760b037d 100644
--- a/test_autogalaxy/imaging/model/test_analysis_imaging.py
+++ b/test_autogalaxy/imaging/model/test_analysis_imaging.py
@@ -37,3 +37,18 @@ def test__figure_of_merit__matches_correct_fit_given_galaxy_profiles(
     fit = ag.FitImaging(dataset=masked_imaging_7x7, galaxies=galaxies)
 
     assert fit.log_likelihood == fit_figure_of_merit
+
+
+def test__register_fit_imaging_pytrees__registers_fit_galaxies_and_dataset_model():
+    from autoarray.abstract_ndarray import _pytree_registered_classes
+    from autoarray.dataset.dataset_model import DatasetModel
+    from autogalaxy.galaxy.galaxies import Galaxies
+    from autogalaxy.imaging.fit_imaging import FitImaging
+
+    ag.AnalysisImaging._register_fit_imaging_pytrees()
+
+    assert FitImaging in _pytree_registered_classes
+    assert DatasetModel in _pytree_registered_classes
+    assert Galaxies in _pytree_registered_classes
+
+