diff --git a/optimistix/_ad.py b/optimistix/_ad.py
index 2ea2a79..e0523c4 100644
--- a/optimistix/_ad.py
+++ b/optimistix/_ad.py
@@ -88,9 +88,7 @@ def _is_none(x):
 
 
 def _for_jac(root, args):
-    fn_rewrite, residual, _inputs = args
-    iterate, inputs, while_loop = _inputs
-    del iterate, while_loop
+    fn_rewrite, residual, inputs = args
     return fn_rewrite(root, residual, inputs)
 
 
@@ -114,9 +112,7 @@ def _implicit_impl_jvp(primals, tangents):
 
     def _for_jvp(_diff):
         _inputs = eqx.combine(_diff, nondiff)
-        iterate, inputs, while_loop = _inputs
-        del iterate, while_loop
-        return fn_rewrite(root, residual, inputs)
+        return fn_rewrite(root, residual, _inputs)
 
     operator = lx.JacobianLinearOperator(
         _for_jac, root, (fn_rewrite, residual, inputs), tags=tags
diff --git a/optimistix/_adjoint.py b/optimistix/_adjoint.py
index 736b111..4a679cb 100644
--- a/optimistix/_adjoint.py
+++ b/optimistix/_adjoint.py
@@ -125,12 +125,7 @@ def apply(self, primal_fn, rewrite_fn, inputs, tags):
         while_loop = ft.partial(
             eqxi.while_loop, kind="checkpointed", checkpoints=self.checkpoints
         )
-        return primal_fn(inputs, while_loop)
-
-
-def _primal_fn(inputs):
-    primal_fn, inputs, while_loop = inputs
-    return primal_fn(inputs, while_loop)
+        return primal_fn(inputs + (while_loop,))
 
 
 class ImplicitAdjoint(AbstractAdjoint):
@@ -149,8 +144,8 @@ class ImplicitAdjoint(AbstractAdjoint):
     linear_solver: lx.AbstractLinearSolver = lx.AutoLinearSolver(well_posed=None)
 
     def apply(self, primal_fn, rewrite_fn, inputs, tags):
-        _inputs = (primal_fn, inputs, ft.partial(eqxi.while_loop, kind="lax"))
-        return implicit_jvp(_primal_fn, rewrite_fn, _inputs, tags, self.linear_solver)
+        inputs = inputs + (ft.partial(eqxi.while_loop, kind="lax"),)
+        return implicit_jvp(primal_fn, rewrite_fn, inputs, tags, self.linear_solver)
 
 
 RecursiveCheckpointAdjoint.__init__.__doc__ = """**Arguments:**
diff --git a/optimistix/_iterate.py b/optimistix/_iterate.py
index bf49210..834bff3 100644
--- a/optimistix/_iterate.py
+++ b/optimistix/_iterate.py
@@ -216,8 +216,19 @@ def _zero(x):
         return x
 
 
-def _iterate(inputs, while_loop):
-    fn, solver, y0, args, options, max_steps, f_struct, aux_struct, tags = inputs
+def _iterate(inputs):
+    (
+        fn,
+        solver,
+        y0,
+        args,
+        options,
+        max_steps,
+        f_struct,
+        aux_struct,
+        tags,
+        while_loop,
+    ) = inputs
     del inputs
     static_leaf = lambda x: isinstance(x, eqxi.Static)
     f_struct = jtu.tree_map(lambda x: x.value, f_struct, is_leaf=static_leaf)
diff --git a/tests/helpers.py b/tests/helpers.py
index 7502a72..ed56845 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -785,4 +785,4 @@ class PiggybackAdjoint(optx.AbstractAdjoint):
     def apply(self, primal_fn, rewrite_fn, inputs, tags):
         del rewrite_fn, tags
         while_loop = ft.partial(eqxi.while_loop, kind="lax")
-        return primal_fn(inputs, while_loop)
+        return primal_fn(inputs + (while_loop,))