GraphQLBundle: Type error introduced in 1.2.0

Works well in 1.1.0

    #[GQL\Access('isAuthenticated()')]
    #[GQL\Mutation(name: 'removeCasesFromPlan')]
    #[GQL\Arg(name: 'planId', type: 'String!')]
    #[GQL\Arg(name: 'cases', type: '[String!]!')]
    public function removeCase(string $planId, array $cases = []): TestPlan
    {

However in 1.2.0

Argument n°2 "$cases" on method "removeCase" cannot be auto-guessed from the following type guessers:                                                   
[Type Hint] No corresponding GraphQL type found for builtin type "array"