return nil, err
				}
				nonExistentUsers = append(nonExistentUsers, ndn.String())
				continue
			}
			return nil, err
		}
		if len(searchResult.Entries) == 0 {
			// DN was not found - this means this user account is
			// expired.
			ndn, err := ldap.ParseDN(dn)
			if err != nil {
				return nil, err
			}
			nonExistentUsers = append(nonExistentUsers, ndn.String())
		}
	}