diff --git a/dune-project b/dune-project
index 1b6ec35a2..066d1a23e 100644
--- a/dune-project
+++ b/dune-project
@@ -34,7 +34,7 @@
   (ocaml
    (and
     (>= "4.06")
-    (< "5.3")))
+    (< "5.4")))
   (ocamlfind :build)
   (dune-build-info
    (>= 2.9.3))
@@ -57,7 +57,7 @@
   (ocaml
    (and
     (>= "4.06")
-    (< "5.3")))
+    (< "5.4")))
   (reason
    (= :version))
   (utop
diff --git a/reason.opam b/reason.opam
index 06bf876a7..a5297417f 100644
--- a/reason.opam
+++ b/reason.opam
@@ -16,7 +16,7 @@ homepage: "https://reasonml.github.io/"
 bug-reports: "https://github.com/reasonml/reason/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.06" & < "5.3"}
+  "ocaml" {>= "4.06" & < "5.4"}
   "ocamlfind" {build}
   "dune-build-info" {>= "2.9.3"}
   "menhir" {>= "20180523"}
diff --git a/rtop.opam b/rtop.opam
index ef1ea2eb3..32619d750 100644
--- a/rtop.opam
+++ b/rtop.opam
@@ -14,7 +14,7 @@ homepage: "https://reasonml.github.io/"
 bug-reports: "https://github.com/reasonml/reason/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.06" & < "5.3"}
+  "ocaml" {>= "4.06" & < "5.4"}
   "reason" {= version}
   "utop" {>= "2.0"}
   "cppo"