diff --git a/cinder/files/backend/_ceph.conf b/cinder/files/backend/_ceph.conf
index b226d77..c57483d 100644
--- a/cinder/files/backend/_ceph.conf
+++ b/cinder/files/backend/_ceph.conf
@@ -22,7 +22,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ backend.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ backend.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/juno/cinder.conf.controller.Debian b/cinder/files/juno/cinder.conf.controller.Debian
index 1a712c4..65bceb1 100644
--- a/cinder/files/juno/cinder.conf.controller.Debian
+++ b/cinder/files/juno/cinder.conf.controller.Debian
@@ -265,7 +265,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/juno/cinder.conf.volume.Debian b/cinder/files/juno/cinder.conf.volume.Debian
index 283fbff..9888ad8 100644
--- a/cinder/files/juno/cinder.conf.volume.Debian
+++ b/cinder/files/juno/cinder.conf.volume.Debian
@@ -329,7 +329,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/kilo/cinder.conf.controller.Debian b/cinder/files/kilo/cinder.conf.controller.Debian
index eba437b..bb8320f 100644
--- a/cinder/files/kilo/cinder.conf.controller.Debian
+++ b/cinder/files/kilo/cinder.conf.controller.Debian
@@ -302,7 +302,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/kilo/cinder.conf.volume.Debian b/cinder/files/kilo/cinder.conf.volume.Debian
index 4acd2fc..f820362 100644
--- a/cinder/files/kilo/cinder.conf.volume.Debian
+++ b/cinder/files/kilo/cinder.conf.volume.Debian
@@ -366,7 +366,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/liberty/cinder.conf.controller.Debian b/cinder/files/liberty/cinder.conf.controller.Debian
index 680fb64..53b1296 100644
--- a/cinder/files/liberty/cinder.conf.controller.Debian
+++ b/cinder/files/liberty/cinder.conf.controller.Debian
@@ -315,7 +315,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ controller.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)
diff --git a/cinder/files/liberty/cinder.conf.volume.Debian b/cinder/files/liberty/cinder.conf.volume.Debian
index 8e61ac2..12582c1 100644
--- a/cinder/files/liberty/cinder.conf.volume.Debian
+++ b/cinder/files/liberty/cinder.conf.volume.Debian
@@ -360,7 +360,7 @@
 # Flatten volumes created from snapshots to remove dependency
 # from volume to snapshot (boolean value)
 #rbd_flatten_volume_from_snapshot=false
-rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', 'false') }}
+rbd_flatten_volume_from_snapshot={{ volume.storage.get('flatten_volume_from_snapshot', False)|lower }}
 
 # The libvirt uuid of the secret for the rbd_user volumes
 # (string value)