diff --git a/CHANGES.md b/CHANGES.md
index 7ad788faa..1322fe29b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,10 @@
+merlin 5.4.1
+============
+Mon Jan 13 10:55:42 CET 2025
+
+  + ocaml-index
+    - Bump magic number after index file format change (#1886)
+
 merlin 5.4
 ==========
 Fri Jan 10 17:55:42 CET 2025
diff --git a/ocaml-index.opam b/ocaml-index.opam
index f0615f66c..3af947b0d 100644
--- a/ocaml-index.opam
+++ b/ocaml-index.opam
@@ -1,4 +1,3 @@
-# This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
 synopsis: "A tool that indexes value usages from cmt files"
 description:
@@ -10,8 +9,8 @@ homepage: "https://github.com/ocaml/merlin/ocaml-index"
 bug-reports: "https://github.com/ocaml/merlin/issues"
 depends: [
   "dune" {>= "3.0.0"}
-  "ocaml" {>= "5.2"}
-  "merlin-lib" {>= "5.1-502"}
+  "ocaml" {>= "5.3"}
+  "merlin-lib" {= version}
   "odoc" {with-doc}
 ]
 build: [
diff --git a/src/ocaml/utils/config.ml b/src/ocaml/utils/config.ml
index 0b8242ee1..87c6a4bfc 100644
--- a/src/ocaml/utils/config.ml
+++ b/src/ocaml/utils/config.ml
@@ -49,7 +49,7 @@ and ast_impl_magic_number = "Caml1999M035"
 and ast_intf_magic_number = "Caml1999N035"
 and cmxs_magic_number = "Caml1999D035"
 and cmt_magic_number = "Caml1999T035"
-and index_magic_number = "Merl2023I002"
+and index_magic_number = "Merl2023I003"
 
 let interface_suffix = ref ".mli"
 let flat_float_array = true