diff --git a/kernel_tuner/runners/parallel.py b/kernel_tuner/runners/parallel.py
index 8884b89e..e8134116 100644
--- a/kernel_tuner/runners/parallel.py
+++ b/kernel_tuner/runners/parallel.py
@@ -1,7 +1,5 @@
-import logging
 import ray
 import sys
-import os
 from ray.util.actor_pool import ActorPool
 from time import perf_counter
 from collections import deque
@@ -9,7 +7,6 @@
 
 from kernel_tuner.core import DeviceInterface
 from kernel_tuner.runners.runner import Runner
-from kernel_tuner.runners.ray.remote_actor import RemoteActor
 from kernel_tuner.util import get_num_devices, GPUTypeMismatchError
 from kernel_tuner.runners.ray.cache_manager import CacheManager
 from kernel_tuner.strategies.common import create_actor_on_device, initialize_ray
diff --git a/kernel_tuner/runners/ray/remote_actor.py b/kernel_tuner/runners/ray/remote_actor.py
index 533dea5b..c0743ad2 100644
--- a/kernel_tuner/runners/ray/remote_actor.py
+++ b/kernel_tuner/runners/ray/remote_actor.py
@@ -1,6 +1,4 @@
 import ray
-import sys
-import copy
 
 from kernel_tuner.runners.sequential import SequentialRunner
 from kernel_tuner.runners.simulation import SimulationRunner
diff --git a/kernel_tuner/strategies/ensemble.py b/kernel_tuner/strategies/ensemble.py
index 2a19f9f7..9cdc0b90 100644
--- a/kernel_tuner/strategies/ensemble.py
+++ b/kernel_tuner/strategies/ensemble.py
@@ -1,22 +1,9 @@
-import random
-import sys
-import os
-import ray
-import copy
-import logging
 import warnings
-from collections import deque
 
-import numpy as np
-
-from kernel_tuner import util
 from kernel_tuner.searchspace import Searchspace
-from kernel_tuner.strategies import common
-from kernel_tuner.strategies.common import CostFunc, scale_from_params, check_num_devices, create_actor_on_device, initialize_ray
+from kernel_tuner.strategies.common import initialize_ray
 from kernel_tuner.runners.simulation import SimulationRunner
-from kernel_tuner.runners.ray.remote_actor import RemoteActor
 from kernel_tuner.util import get_num_devices
-from kernel_tuner.runners.ray.cache_manager import CacheManager
 from kernel_tuner.runners.parallel import ParallelRunner
 
 from kernel_tuner.strategies import (