diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c1b82958f1..0c95d0c0c7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -9,6 +9,9 @@ on:
     # Prime the caches every Monday
     - cron: 0 1 * * MON
 
+env:
+  DUNE_CONFIG__BACKGROUND_SANDBOXES: disabled
+
 jobs:
   build:
     strategy:
diff --git a/dune-project b/dune-project
index 386c34bae9..d2da6903bf 100644
--- a/dune-project
+++ b/dune-project
@@ -22,7 +22,6 @@
   (num :with-test)
   (ppx_expect (and (>= v0.14.2) :with-test))
   (ppxlib (>= 0.15.0))
-  (dune (< 3.9))
   (re :with-test)
   (cmdliner (>= 1.1.0))
   (sedlex (>= 2.3))
diff --git a/js_of_ocaml-compiler.opam b/js_of_ocaml-compiler.opam
index 5ce6c28329..a7aea9aa62 100644
--- a/js_of_ocaml-compiler.opam
+++ b/js_of_ocaml-compiler.opam
@@ -12,11 +12,11 @@ homepage: "https://ocsigen.org/js_of_ocaml/latest/manual/overview"
 doc: "https://ocsigen.org/js_of_ocaml/latest/manual/overview"
 bug-reports: "https://github.com/ocsigen/js_of_ocaml/issues"
 depends: [
+  "dune" {>= "3.7"}
   "ocaml" {>= "4.08" & < "5.2"}
   "num" {with-test}
   "ppx_expect" {>= "v0.14.2" & with-test}
   "ppxlib" {>= "0.15.0"}
-  "dune" {>= "3.7" & < "3.9"}
   "re" {with-test}
   "cmdliner" {>= "1.1.0"}
   "sedlex" {>= "2.3"}