diff --git a/lower-constraints.txt b/lower-constraints.txt
index d1134653b1d7..d54919acd01d 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -22,7 +22,7 @@ deprecation==2.0
 dogpile.cache==0.6.5
 enum34==1.0.4
 enum-compat==0.0.2
-eventlet==0.20.0
+eventlet==0.21.0
 extras==1.0.0
 fasteners==0.14.1
 fixtures==3.0.0
diff --git a/nova/monkey_patch.py b/nova/monkey_patch.py
index 1a610248ad4e..6999c7ebe749 100644
--- a/nova/monkey_patch.py
+++ b/nova/monkey_patch.py
@@ -66,14 +66,6 @@ def _monkey_patch():
     import threading
     orig_threading.current_thread.__globals__['_active'] = threading._active
 
-    # NOTE(rpodolyaka): import oslo_service first, so that it makes eventlet
-    # hub use a monotonic clock to avoid issues with drifts of system time (see
-    # LP 1510234 for details)
-    # NOTE(mdbooth): This was fixed in eventlet 0.21.0. Remove when bumping
-    # eventlet version.
-    import oslo_service  # noqa
-    eventlet.hubs.use_hub("oslo_service:service_hub")
-
     # NOTE(mdbooth): Log here instead of earlier to avoid loading oslo logging
     # before monkey patching.
     # NOTE(mdbooth): Ideally we would raise an exception here, as this is
diff --git a/requirements.txt b/requirements.txt
index 66e8b7ca43ce..88fa7ee84e4d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 SQLAlchemy>=1.2.19 # MIT
 decorator>=3.4.0 # BSD
-eventlet!=0.20.1,>=0.20.0 # MIT
+eventlet>=0.21.0 # MIT
 Jinja2>=2.10 # BSD License (3 clause)
 keystonemiddleware>=4.20.0 # Apache-2.0
 lxml!=3.7.0,>=3.4.1 # BSD