diff --git a/vendors/ocplib-json-typed/lib_json_typed_browser/dune b/vendors/ocplib-json-typed/lib_json_typed_browser/dune
index 95f627b0c..f9195ef7e 100644
--- a/vendors/ocplib-json-typed/lib_json_typed_browser/dune
+++ b/vendors/ocplib-json-typed/lib_json_typed_browser/dune
@@ -1,7 +1,7 @@
 (library
  (name        ocplib_json_typed_browser)
  (public_name ocplib-json-typed-browser)
- (flags (:standard -w -9))
+ (flags (:standard -w -9 -open Js_of_ocaml))
  (synopsis "Native browser representation of JSON documents")
  (libraries ocplib-json-typed js_of_ocaml)
  (wrapped false))
diff --git a/vendors/ocplib-json-typed/lib_json_typed_browser/ocplib-json-typed-browser.opam b/vendors/ocplib-json-typed/lib_json_typed_browser/ocplib-json-typed-browser.opam
index 98017e608..c8c14c33b 100644
--- a/vendors/ocplib-json-typed/lib_json_typed_browser/ocplib-json-typed-browser.opam
+++ b/vendors/ocplib-json-typed/lib_json_typed_browser/ocplib-json-typed-browser.opam
@@ -12,5 +12,5 @@ run-test: [ "dune" "runtest" "-p" name "-j" jobs ]
 depends: [
   "dune" {build & >= "1.0.1"}
   "ocplib-json-typed" {= "0.6" }
-  "js_of_ocaml" {>= "3.1.0"}
+  "js_of_ocaml" {>= "3.3.0"}
 ]