diff --git a/units/systemd-nspawn@.service.in b/units/systemd-nspawn@.service.in
index 03349931d9d81..2e79adff447be 100644
--- a/units/systemd-nspawn@.service.in
+++ b/units/systemd-nspawn@.service.in
@@ -39,6 +39,7 @@ DeviceAllow=char-pts rw
 # implement the --image= option. Add these here, too.
 DeviceAllow=/dev/loop-control rw
 DeviceAllow=block-loop rw
+DeviceAllow=block-blkext rw
 
 [Install]
 WantedBy=machines.target