diff --git a/PVE/Storage/CephFSPlugin.pm b/PVE/Storage/CephFSPlugin.pm
index de1499c..1bfdd01 100644
--- a/PVE/Storage/CephFSPlugin.pm
+++ b/PVE/Storage/CephFSPlugin.pm
@@ -66,6 +66,10 @@ sub cephfs_mount {
 	$cmd = ['/bin/mount', '-t', 'ceph', $source, $mountpoint, '-o', "name=$cmd_option->{userid}"];
 	push @$cmd, '-o', "secretfile=$secretfile" if defined($secretfile);
     }
+    # tell systemd that we're network dependent, else it umounts us to late on
+    # shutdown, when we couldn't connect to the active MDS and thus unmount
+    # hangs and delays shutdown/reboot (man systemd.mount)
+    push @$cmd, '-o', '_netdev';
 
     if ($scfg->{options}) {
 	push @$cmd, '-o', $scfg->{options};