diff --git a/mbpo/optimizers/base_optimizer.py b/mbpo/optimizers/base_optimizer.py
index 00b1a8c..02b511f 100644
--- a/mbpo/optimizers/base_optimizer.py
+++ b/mbpo/optimizers/base_optimizer.py
@@ -20,6 +20,10 @@ def __init__(self, system: System | None = None, key: jr.PRNGKey = jr.PRNGKey(0)
     def set_system(self, system: System):
         self.system = system
 
+    @property
+    def can_act_in_batches(self):
+        return True
+
     @abstractmethod
     def act(self,
             obs: chex.Array,
diff --git a/mbpo/optimizers/trajectory_optimizers/icem_optimizer.py b/mbpo/optimizers/trajectory_optimizers/icem_optimizer.py
index 57bc0c4..36fa2f7 100755
--- a/mbpo/optimizers/trajectory_optimizers/icem_optimizer.py
+++ b/mbpo/optimizers/trajectory_optimizers/icem_optimizer.py
@@ -10,12 +10,11 @@
 
 from jax import vmap, jit
 from jax.nn import relu
-from jax.numpy import sqrt, newaxis
-from jax.numpy.fft import irfft, rfftfreq
+from brax.training.replay_buffers import ReplayBufferState
 from jaxtyping import Float, Array, Key, Scalar
 
 from mbpo.optimizers.base_optimizer import BaseOptimizer
-from mbpo.systems.base_systems import System, SystemParams
+from mbpo.systems.base_systems import System
 from mbpo.systems.dynamics.base_dynamics import DynamicsParams
 from mbpo.systems.rewards.base_rewards import RewardParams
 from mbpo.utils.optimizer_utils import rollout_actions
@@ -119,7 +118,7 @@ def __init__(self,
         else:
             self.summarize_cost_samples = jnp.mean
 
-    def init(self, key: chex.Array) -> iCemOptimizerState:
+    def init(self, key: chex.Array, true_buffer_state: ReplayBufferState | None = None) -> iCemOptimizerState:
         assert self.system is not None, "iCem optimizer requires system to be defined."
         init_key, dummy_buffer_key, key = jax.random.split(key, 3)
         system_params = self.system.init_params(init_key)
@@ -280,6 +279,10 @@ def __init__(self,
     def set_system(self, system: System):
         super().set_system(system)
 
+    @property
+    def can_act_in_batches(self):
+        return False
+
     def init(self,
              key: chex.PRNGKey,
              true_buffer_state = None) -> iCemOptimizerState: