diff --git a/lxd/storage/drivers/driver_cephfs_volumes.go b/lxd/storage/drivers/driver_cephfs_volumes.go
index <HASH>..<HASH> 100644
--- a/lxd/storage/drivers/driver_cephfs_volumes.go
+++ b/lxd/storage/drivers/driver_cephfs_volumes.go
@@ -343,7 +343,8 @@ func (d *cephfs) MountVolume(vol Volume, op *operations.Operation) (bool, error)
 }
 
 // UnmountVolume clears any runtime state for the volume.
-func (d *cephfs) UnmountVolume(vol Volume, op *operations.Operation) (bool, error) {
+// As driver doesn't have volumes to unmount it returns false indicating the volume was already unmounted.
+func (d *cephfs) UnmountVolume(vol Volume, keepBlockDev bool, op *operations.Operation) (bool, error) {
 	return false, nil
 }
lxd/storage/drivers/driver/cephfs/volumes: Adds keepBlockDev arg to UnmountVolume