diff --git a/cinder/backup/manager.py b/cinder/backup/manager.py
index 7c7f7f7ee70..f6ebefd7649 100644
--- a/cinder/backup/manager.py
+++ b/cinder/backup/manager.py
@@ -83,7 +83,7 @@ QUOTAS = quota.QUOTAS
 class BackupManager(manager.SchedulerDependentManager):
     """Manages backup of block storage devices."""
 
-    RPC_API_VERSION = '2.0'
+    RPC_API_VERSION = backup_rpcapi.BackupAPI.RPC_API_VERSION
 
     target = messaging.Target(version=RPC_API_VERSION)
 
diff --git a/cinder/scheduler/manager.py b/cinder/scheduler/manager.py
index 86eec42b6b9..ae0fdece412 100644
--- a/cinder/scheduler/manager.py
+++ b/cinder/scheduler/manager.py
@@ -37,6 +37,7 @@ from cinder import objects
 from cinder import quota
 from cinder import rpc
 from cinder.scheduler.flows import create_volume
+from cinder.scheduler import rpcapi as scheduler_rpcapi
 from cinder.volume import rpcapi as volume_rpcapi
 
 
@@ -60,7 +61,7 @@ class SchedulerManager(manager.Manager):
     # create_consistencygroup(), create_volume(), migrate_volume_to_host(),
     # retype() and manage_existing() in v3.0 of RPC API.
 
-    RPC_API_VERSION = '2.1'
+    RPC_API_VERSION = scheduler_rpcapi.SchedulerAPI.RPC_API_VERSION
 
     target = messaging.Target(version=RPC_API_VERSION)
 
diff --git a/cinder/volume/manager.py b/cinder/volume/manager.py
index 5c2ccb8fdc4..89df3f5b97f 100644
--- a/cinder/volume/manager.py
+++ b/cinder/volume/manager.py
@@ -157,7 +157,7 @@ MAPPING = {
 class VolumeManager(manager.SchedulerDependentManager):
     """Manages attachable block storage devices."""
 
-    RPC_API_VERSION = '2.3'
+    RPC_API_VERSION = volume_rpcapi.VolumeAPI.RPC_API_VERSION
 
     target = messaging.Target(version=RPC_API_VERSION)