typed-racket `struct`'s `#:methods` missing in Typed Racket

What version of Racket are you using?

8.10

What program did you run?

In normal racket:

#lang racket/base

(require racket/generic)

(define-generics testable
  (test testable))
  
(struct myst (sth)
  #:methods gen:testable
  [(define (test self) (myst-sth self))])

(define x (myst "3648"))
(test x)  ;; => "3648"

However, in Typed Racket:

#lang typed/racket/base

(require racket/generic)

(define-generics testable
  (test testable))
  
(struct myst ([sth : Any])
  #:methods gen:testable
  [(define (test self) (myst-sth self))])

(define x (myst "3648"))
(test x)  ;; => ERROR: struct: expected one of these literals: #:mutable, #:transparent, #:prefab, #:constructor-name, #:extra-constructor-name, #:type-name, #:guard, or #:property

If you got an error message, please include it here.

HelloWorld.rkt:8:0: struct: expected one of these literals: #:mutable, #:transparent, #:prefab, #:constructor-name, #:extra-constructor-name, #:type-name, #:guard, or #:property
  at: #:methods
  in: (struct myst ((sth : Any)) #:methods gen:testable ((define (test self) (myst-sth self))))
  parsing context: 
   while parsing typed structure type options
    term: (#:methods gen:testable ((define (test self) (m...
    location: <pkgs>/yacp/HelloWorld.rkt:8:0
  location...:
   HelloWorld.rkt:9:2
  context...:
   /Applications/Racket v8.10/collects/syntax/parse/private/runtime-report.rkt:739:0: error/report
   /Applications/Racket v8.10/collects/syntax/parse/private/runtime-report.rkt:25:0: call-current-failure-handler
   /Applications/Racket v8.10/share/pkgs/typed-racket-lib/typed-racket/tc-setup.rkt:71:0: tc-setup
   /Applications/Racket v8.10/share/pkgs/typed-racket-lib/typed-racket/typed-racket.rkt:22:4