diff --git a/dune-project b/dune-project
index 335194ae48..dae50bd073 100644
--- a/dune-project
+++ b/dune-project
@@ -21,6 +21,7 @@
  ; (tags
  ; (topics "to describe" your project))
  (depends
+  brr
   (ocaml
    (>= 5.2.0))
   (menhir
diff --git a/hazel.opam b/hazel.opam
index 36a81b933a..78edd3c215 100644
--- a/hazel.opam
+++ b/hazel.opam
@@ -8,6 +8,7 @@ homepage: "https://github.com/hazelgrove/hazel"
 bug-reports: "https://github.com/hazelgrove/hazel/issues"
 depends: [
   "dune" {>= "3.16"}
+  "brr"
   "ocaml" {>= "5.2.0"}
   "menhir" {>= "2.0"}
   "yojson"
diff --git a/hazel.opam.locked b/hazel.opam.locked
index 31fd8b2c15..a6715844a6 100644
--- a/hazel.opam.locked
+++ b/hazel.opam.locked
@@ -29,6 +29,7 @@ depends: [
   "bignum" {= "v0.16.0"}
   "bigstringaf" {= "0.9.1"}
   "bin_prot" {= "v0.16.0"}
+  "brr" {= "0.0.6"}
   "camlp-streams" {= "5.0.1"}
   "chrome-trace" {= "3.16.0"}
   "cmdliner" {= "1.3.0"}
@@ -65,6 +66,7 @@ depends: [
   "js_of_ocaml" {= "5.8.2"}
   "js_of_ocaml-compiler" {= "5.8.2"}
   "js_of_ocaml-ppx" {= "5.8.2"}
+  "js_of_ocaml-toplevel" {= "5.8.2"}
   "js_of_ocaml_patches" {= "v0.16.0"}
   "jsonrpc" {= "1.19.0"}
   "jst-config" {= "v0.16.0"}
diff --git a/src/haz3lweb/Main.re b/src/haz3lweb/Main.re
index cf0269bf45..45d7ed908c 100644
--- a/src/haz3lweb/Main.re
+++ b/src/haz3lweb/Main.re
@@ -2,7 +2,6 @@ open Util;
 open Js_of_ocaml;
 open Incr_dom;
 open Haz3lweb;
-
 let scroll_to_caret = ref(true);
 let edit_action_applied = ref(true);
 let last_edit_action = ref(JsUtil.timestamp());
@@ -76,6 +75,7 @@ module App = {
   module State = State;
 
   let on_startup = (~schedule_action, m: Model.t) => {
+    Brr_poke.define();
     let _ =
       observe_font_specimen("font-specimen", fm =>
         schedule_action(Haz3lweb.Update.SetMeta(FontMetrics(fm)))
diff --git a/src/haz3lweb/dune b/src/haz3lweb/dune
index 8d25155dc5..1d24323cc9 100644
--- a/src/haz3lweb/dune
+++ b/src/haz3lweb/dune
@@ -9,6 +9,9 @@
  (name workerServer)
  (modules WorkerServer)
  (libraries
+  brr
+  brr.poke
+  str
   incr_dom
   virtual_dom.input_widgets
   util
@@ -59,7 +62,10 @@
  (name main)
  (modules Main)
  (libraries ppx_yojson_conv.expander haz3lweb)
+ (link_flags -linkall)
  (modes js)
+ (js_of_ocaml
+  (flags :standard --toplevel))
  (preprocess
   (pps
    ppx_yojson_conv
@@ -73,13 +79,17 @@
  (modules Worker)
  (libraries workerServer)
  (modes js)
+ (link_flags -linkall)
+ (js_of_ocaml
+  (flags :standard --toplevel))
  (preprocess
   (pps js_of_ocaml-ppx)))
 
 (env
  (dev
   (js_of_ocaml
-   (flags :standard --debuginfo --noinline --dynlink --linkall --sourcemap)))
+   (flags
+    (:standard --debuginfo --noinline --dynlink --linkall --sourcemap))))
  (release
   (js_of_ocaml
    (flags (:standard)))))