diff --git a/compiler_opt/es/blackbox_evaluator.py b/compiler_opt/es/blackbox_evaluator.py
index 2bd68c51..787ae61d 100644
--- a/compiler_opt/es/blackbox_evaluator.py
+++ b/compiler_opt/es/blackbox_evaluator.py
@@ -25,6 +25,7 @@
 from compiler_opt.rl import corpus
 from compiler_opt.es import blackbox_optimizers
 from compiler_opt.distributed import buffered_scheduler
+from compiler_opt.rl import policy_saver
 
 
 class BlackboxEvaluator(metaclass=abc.ABCMeta):
@@ -36,8 +37,8 @@ def __init__(self, train_corpus: corpus.Corpus):
 
   @abc.abstractmethod
   def get_results(
-      self, pool: FixedWorkerPool,
-      perturbations: List[bytes]) -> List[concurrent.futures.Future]:
+      self, pool: FixedWorkerPool, perturbations: List[policy_saver.Policy]
+  ) -> List[concurrent.futures.Future]:
     raise NotImplementedError()
 
   @abc.abstractmethod
@@ -66,8 +67,8 @@ def __init__(self, train_corpus: corpus.Corpus,
     super().__init__(train_corpus)
 
   def get_results(
-      self, pool: FixedWorkerPool,
-      perturbations: List[bytes]) -> List[concurrent.futures.Future]:
+      self, pool: FixedWorkerPool, perturbations: List[policy_saver.Policy]
+  ) -> List[concurrent.futures.Future]:
     if not self._samples:
       for _ in range(self._total_num_perturbations):
         sample = self._train_corpus.sample(self._num_ir_repeats_within_worker)
diff --git a/compiler_opt/es/blackbox_learner.py b/compiler_opt/es/blackbox_learner.py
index 984ef5a3..c4e82b62 100644
--- a/compiler_opt/es/blackbox_learner.py
+++ b/compiler_opt/es/blackbox_learner.py
@@ -223,8 +223,10 @@ def _save_model(self) -> None:
   def get_model_weights(self) -> npt.NDArray[np.float32]:
     return self._model_weights
 
-  def _get_policy_as_bytes(self,
-                           perturbation: npt.NDArray[np.float32]) -> bytes:
+  # TODO: The current conversion is inefficient (performance-wise). We should
+  # consider doing this on the worker side.
+  def _get_policy_from_perturbation(
+      self, perturbation: npt.NDArray[np.float32]) -> policy_saver.Policy:
     sm = tf.saved_model.load(self._tf_policy_path)
     # devectorize the perturbation
     policy_utils.set_vectorized_parameters_for_policy(sm, perturbation)
@@ -242,7 +244,7 @@ def _get_policy_as_bytes(self,
 
       # create and return policy
       policy_obj = policy_saver.Policy.from_filesystem(tfl_dir)
-      return policy_obj.policy
+      return policy_obj
 
   def run_step(self, pool: FixedWorkerPool) -> None:
     """Run a single step of blackbox learning.
@@ -258,14 +260,12 @@ def run_step(self, pool: FixedWorkerPool) -> None:
           p for p in initial_perturbations for p in (p, -p)
       ]
 
-    # convert to bytes for compile job
-    # TODO: current conversion is inefficient.
-    # consider doing this on the worker side
-    perturbations_as_bytes = []
+    perturbations_as_policies = []
     for perturbation in initial_perturbations:
-      perturbations_as_bytes.append(self._get_policy_as_bytes(perturbation))
+      perturbations_as_policies.append(
+          self._get_policy_from_perturbation(perturbation))
 
-    results = self._evaluator.get_results(pool, perturbations_as_bytes)
+    results = self._evaluator.get_results(pool, perturbations_as_policies)
     rewards = self._evaluator.get_rewards(results)
 
     num_pruned = _prune_skipped_perturbations(initial_perturbations, rewards)
diff --git a/compiler_opt/es/blackbox_learner_test.py b/compiler_opt/es/blackbox_learner_test.py
index cb5667c5..5f74a13a 100644
--- a/compiler_opt/es/blackbox_learner_test.py
+++ b/compiler_opt/es/blackbox_learner_test.py
@@ -45,7 +45,8 @@ def __init__(self, arg, *, kwarg):
     self._kwarg = kwarg
     self.function_value = 0.0
 
-  def compile(self, policy: bytes, samples: List[corpus.ModuleSpec]) -> float:
+  def compile(self, policy: policy_saver.Policy,
+              samples: List[corpus.ModuleSpec]) -> float:
     if policy and samples:
       self.function_value += 1.0
       return self.function_value