diff --git a/jax/_src/interpreters/ad.py b/jax/_src/interpreters/ad.py
index a3dc72ddc244..560feeee484f 100644
--- a/jax/_src/interpreters/ad.py
+++ b/jax/_src/interpreters/ad.py
@@ -168,8 +168,10 @@ def direct_linearize(traceable, primals, kwargs, *, has_aux=False, tag=None):
   with core.take_current_trace() as parent_trace:
     tangent_trace = pe.DynamicJaxprTrace()
     tangents = [tangent_trace.new_arg(get_aval(p).to_tangent_aval()) for p in primals]
+    tangents = [Zero.from_primal_value(t) if dtype(t) == float0 else t for t in tangents]
     linearize_trace = LinearizeTrace(parent_trace, tangent_trace, tag=tag)
     tracers = [LinearizeTracer(linearize_trace, p, t) for p, t in zip(primals, tangents)]
+    tracers = [t.full_lower() for t in tracers]
     with core.set_current_trace(linearize_trace):
       if has_aux:
         ans, aux = traceable.call_wrapped(*tracers)
@@ -622,8 +624,8 @@ def process_custom_vjp_call(self, prim, fun, fwd, bwd, tracers, out_trees,
     res, primals_out = split_list(res_and_primals_out, [res_tree.num_leaves])
     avals_out = [core.get_aval(x).to_tangent_aval() for x in primals_out]
 
+    tangents_in = map(instantiate_zeros, tangents_in)
     with core.set_current_trace(self.tangent_trace):
-      tangents_in = map(instantiate_zeros, tangents_in)
       tangents_out = custom_lin_p.bind(
         *res, *tangents_in, num_res=res_tree.num_leaves, bwd=bwd,
         out_avals=avals_out, symbolic_zeros=symbolic_zeros)