diff --git a/upgrade.py b/upgrade.py
index ec8d9104..8a4b0851 100644
--- a/upgrade.py
+++ b/upgrade.py
@@ -445,6 +445,9 @@ def buildRestoreList(self):
 
         self.restore_list += ['var/lib/xcp/verify_certificates']
 
+        # Keep IPv6 enablement/disablement upon upgrades
+        self.restore_list += ['etc/sysctl.d/91-net-ipv6.conf']
+
     completeUpgradeArgs = ['mounts', 'installation-to-overwrite', 'primary-disk', 'backup-partnum', 'logs-partnum', 'net-admin-interface', 'net-admin-bridge', 'net-admin-configuration']
     def completeUpgrade(self, mounts, prev_install, target_disk, backup_partnum, logs_partnum, admin_iface, admin_bridge, admin_config):