Adding GQL schema with lang support

Details

Following instructions here:
https://dgraph.io/docs/graphql/dgraph/#language-support-in-graphql

My Dgraph schema has the following predicate:
label: string @index(term, fulltext) @lang .

I’m getting an error when I try to add the following GraphQL schema:

type Synonym @key(fields: id) {
    id: ID!
    label: String @search(by: [term, fulltext]) @dgraph(pred: "label@en")
}

$ curl -X POST http://192.168.1.2:4002/admin/schema/validate --data-binary @schema.graphql
{"errors":[{"message":"Schema is valid","extensions":{"code":"success"}}]}

$ curl -X POST http://192.168.1.2:4002/admin/schema --data-binary @schema.graphql
{"errors":[{"message":"resolving updateGQLSchema failed because line 2 column 7: Missing colon in type declaration. Got @ (Locations: [{Line: 3, Column: 4}])","extensions":{"code":"Error"}}]}

If i take out the @en from the GraphQL schema, it saves correctly however queries return null for field label because triple objects literals are language specific

What version of Dgraph are you using?

Dgraph Version
$ dgraph version
 

Dgraph version   : v21.03.1
Dgraph codename  : rocket-1
Dgraph SHA-256   : a00b73d583a720aa787171e43b4cb4dbbf75b38e522f66c9943ab2f0263007fe
Commit SHA-1     : ea1cb5f35
Commit timestamp : 2021-06-17 20:38:11 +0530
Branch           : HEAD
Go version       : go1.16.2
jemalloc enabled : true

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</details>

Any insight by the community on this would be greatly appreciated!