diff --git a/dune-project b/dune-project
index 97eb8d7f..5ddf6865 100644
--- a/dune-project
+++ b/dune-project
@@ -28,7 +28,8 @@
   ;; General system dependencies
   (ocaml (>= 5.0.0))
   (reason (>= 3.10.0))
-  melange
+  integers
+  ctypes
 
   ;; Test dependencies
   (alcotest :with-test)
diff --git a/regexp.opam b/regexp.opam
index 22da609b..c1417997 100644
--- a/regexp.opam
+++ b/regexp.opam
@@ -11,7 +11,8 @@ depends: [
   "dune" {>= "3.8"}
   "ocaml" {>= "5.0.0"}
   "reason" {>= "3.10.0"}
-  "melange"
+  "integers"
+  "ctypes"
   "alcotest" {with-test}
   "fmt" {with-test}
   "odoc" {with-doc}