diff --git a/karbor/services/operationengine/engine/executors/thread_pool_executor.py b/karbor/services/operationengine/engine/executors/thread_pool_executor.py
index 2c3bbc9f..f308bb70 100644
--- a/karbor/services/operationengine/engine/executors/thread_pool_executor.py
+++ b/karbor/services/operationengine/engine/executors/thread_pool_executor.py
@@ -11,7 +11,7 @@
 #    under the License.
 
 from collections import defaultdict
-from concurrent import futures
+import futurist
 from oslo_config import cfg
 from oslo_log import log as logging
 from threading import RLock
@@ -39,7 +39,7 @@ class ThreadPoolExecutor(base_executor.ScheduledOperationExecutor):
         if thread_count is None:
             thread_count = CONF.thread_count
 
-        self._pool = futures.ThreadPoolExecutor(thread_count)
+        self._pool = futurist.GreenThreadPoolExecutor(thread_count)
         self._operation_to_run = defaultdict(int)
         self._operation_to_cancel = set()
         self._lock = RLock()
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 95b4b722..2df43ff9 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -29,7 +29,7 @@ extras==1.0.0
 fasteners==0.14.1
 fixtures==3.0.0
 flake8==2.5.5
-futurist==1.6.0
+futurist==1.8.0
 google-auth==1.4.1
 greenlet==0.4.10
 hacking==0.12.0
diff --git a/requirements.txt b/requirements.txt
index 8553b8bc..50a82f4b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -46,3 +46,4 @@ oslo.i18n>=3.15.3 # Apache-2.0
 python-swiftclient>=3.2.0 # Apache-2.0
 python-karborclient>=0.6.0 # Apache-2.0
 abclient>=0.2.3 # Apache-2.0
+futurist>=1.8.0 # Apache-2.0