diff --git a/g5k-postinstall b/g5k-postinstall
index 48253c8451929d496aefcc9bcdd0fbeafe2f362e..d3fc4ab1cbd1bd2a756a95486e5dbb4eda5125da 100755
--- a/g5k-postinstall
+++ b/g5k-postinstall
@@ -916,7 +916,7 @@ if $mysite == 'nancy' and ( $mycluster == 'grcinq' or $mycluster == 'grvingt' )
 end
 
 # Disable Dell OMSA for unsupported clusters (Bug #13598)
-if envrelease =~ /debian11-x64-std/ and $mycluster == 'neowise'
+if envrelease =~ /debian11-x64-std/ and ( $mycluster == 'neowise' or $mycluster == 'sirius' )
   $logger.info 'Running hack: disable Dell services'
   check_chroot(DSTDIR)
   system_or_raise("chroot #{DSTDIR} systemctl disable dsm_sa_datamgrd.service")