SHIELD terms lookup filter AuthorizationException BUG

gistfile1.txt

# Add user 'admin' with default 'admin' role.
./bin/shield/esusers useradd admin -p admin1 -r admin

# create index.
curl -XPUT 'admin:admin1@localhost:9200/customer'

# create a document on the index
curl -XPUT 'admin:admin1@localhost:9200/customer/external/1' -d '
{
  "name" : "John Doe",
  "token" : "token1"
}'

# create additional index for the "terms lookup" filter functionality
curl -XPUT 'admin:admin1@localhost:9200/tokens'

# create document in 'tokens' index
curl -XPUT 'admin:admin1@localhost:9200/tokens/tokens/1' -d '
{
  "group" : "1",
  "tokens" : ["token1", "token2" ]
}'

# search with a terms lookup filter on the "customer" index, referring to the 'tokens' index.

curl -XGET 'admin:admin1@localhost:9200/customer/external/_search' -d '
{
  "query": {
    "filtered": {
      "query": {
        "match_all": {}
      },
      "filter": {
       "terms": {
        "token": {
          "index": "tokens",
          "type": "tokens",
          "id": "1",
          "path": "tokens"
         }
       }
      }
    }
  }
}'


=> org.elasticsearch.shield.authz.AuthorizationException: action [indices:data/read/get] is unauthorized for user [__es_system_user]