diff --git management/univention-directory-manager-modules/scripts/proof_class_b_reverse management/univention-directory-manager-modules/scripts/proof_class_b_reverse
index 0dde7d66c3..9f50b5121d 100755
--- management/univention-directory-manager-modules/scripts/proof_class_b_reverse
+++ management/univention-directory-manager-modules/scripts/proof_class_b_reverse
@@ -34,36 +34,35 @@
 
 from __future__ import print_function
 
-import ldap
 from ldap.filter import filter_format
 import sys
 
+import univention.admin.uldap as uldap
 import univention.config_registry
 
 ucr = univention.config_registry.ConfigRegistry()
 ucr.load()
 
-baseDN = ucr['ldap/base']
-
 if ucr['interfaces/eth0/netmask'] != "255.255.0.0":
        print('Only for Class B')
        sys.exit(1)
 
-lo = ldap.open('localhost', 7389)
-bindpw = open('/etc/ldap.secret').read()
-if bindpw[-1] == '\n':
-       bindpw = bindpw[0:-1]
-       lo.simple_bind_s("cn=admin," + baseDN, bindpw)
+lo, position = uldap.getAdminConnection()
+ldap_base = position.getBase()
 
-computers = lo.search_s(baseDN, ldap.SCOPE_SUBTREE, 'objectClass=univentionHost', ['aRecord'])
+computers = lo.search('objectClass=univentionHost', attr=['aRecord'], base=ldap_base)
 
-for i in range(0, len(computers)):
-       print('DN: %s' % computers[i][0])
-       if 'aRecord' in computers[i][1]:
-               entry = computers[i][1]['aRecord'][0].split('.')[2:4]
-               reverse = lo.search_s('cn=dns,%s' % baseDN, ldap.SCOPE_SUBTREE, filter_format('(&(relativeDomainName=%s)(pTRRecord=%s*))', ('.'.join(entry), ldap.explode_dn(computers[i][0], 1)[0])))
-               if len(reverse) != 0:
-                       print('Wrong DNS Reverse Entry for %s: %s' % (computers[i][0], reverse[0][0]))
-                       entry.reverse()
-                       entry = '.'.join(entry)
-                       lo.modrdn_s(reverse[0][0], 'relativeDomainName=%s' % entry)
+for dn, attribute in computers:
+       print('DN: %s' % dn)
+       entry = attribute['aRecord'][0].split(b'.')[2:4]
+       reverse = lo.search(
+               filter_format('(&(relativeDomainName=%s)(pTRRecord=%s*))',
+               (b'.'.join(entry).decode('utf-8'),
+               ucr.get('hostname'))),
+               base='cn=dns,%s' % ldap_base,
+       )
+       if len(reverse) != 0:
+               print('Wrong DNS Reverse Entry for %s: %s' % (dn, reverse[0][0]))
+               entry.reverse()
+               entry = '.'.join(entry).decode('utf-8')
+               lo.modrdn_s(reverse[0][0], 'relativeDomainName=%s' % entry)