diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f4b114ffc7..64d0651435 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -214,13 +214,7 @@ This is usually the file you want to create to test certain compile behavior wit
 
 The "Playground bundle" is a JS version of the ReScript compiler; including all necessary dependency files (stdlib / belt etc). It is useful for building tools where you want to compile and execute arbitrary ReScript code in the browser.
 
-The ReScript source code is compiled with a tool called [JSOO (js_of_ocaml)](https://ocsigen.org/js_of_ocaml/4.0.0/manual/overview), which uses OCaml bytecode to compile to JavaScript and is part of the bigger OCaml ecosystem.
-
-Install `jsoo` via `opam`:
-
-```sh
-opam install js_of_ocaml.4.0.0
-```
+The ReScript source code is compiled with a tool called [JSOO (js_of_ocaml)](https://ocsigen.org/js_of_ocaml/latest/manual/overview), which uses OCaml bytecode to compile to JavaScript and is part of the bigger OCaml ecosystem.
 
 ### Building the Bundle
 
diff --git a/dune-project b/dune-project
index 0532a0380d..641bdd136d 100644
--- a/dune-project
+++ b/dune-project
@@ -35,7 +35,7 @@
   (cppo
    (= 1.6.9))
   (js_of_ocaml
-   (= 5.8.1))
+   (= 5.9.1))
   (ounit2
    (= 2.2.7))
   (reanalyze
diff --git a/rescript.opam b/rescript.opam
index bc35c92939..4bef5100f5 100644
--- a/rescript.opam
+++ b/rescript.opam
@@ -12,7 +12,7 @@ depends: [
   "yojson" {with-test & = "2.2.2"}
   "ocaml-lsp-server" {with-dev-setup & = "1.19.0"}
   "cppo" {= "1.6.9"}
-  "js_of_ocaml" {= "5.8.1"}
+  "js_of_ocaml" {= "5.9.1"}
   "ounit2" {= "2.2.7"}
   "reanalyze" {= "2.25.1"}
   "dune"