diff --git a/pkgs/development/ocaml-modules/ocaml-lsp/default.nix b/pkgs/development/ocaml-modules/ocaml-lsp/default.nix
index a8178c6ef717..9e512e35f304 100644
--- a/pkgs/development/ocaml-modules/ocaml-lsp/default.nix
+++ b/pkgs/development/ocaml-modules/ocaml-lsp/default.nix
@@ -1,4 +1,5 @@
 { lib
+, ocaml
 , buildDunePackage
 , lsp
 , xdg
@@ -11,18 +12,30 @@
 , merlin-lib
 , astring
 , camlp-streams
+, base
 }:
 
+# Freeze ocaml-lsp-version at 1.17.0 for OCaml 5.0
+#  for which merlin 4.16 is not available
+let lsp_v =
+  if lib.versions.majorMinor ocaml.version == "5.0"
+  then lsp.override { version = "1.17.0"; }
+  else lsp
+; in
+
+let lsp = lsp_v; in
+
 buildDunePackage rec {
   pname = "ocaml-lsp-server";
   inherit (lsp) version src preBuild;
-  duneVersion = "3";
 
   buildInputs = lsp.buildInputs ++ [ lsp re ]
   ++ lib.optional (lib.versionAtLeast version "1.9") spawn
   ++ lib.optionals (lib.versionAtLeast version "1.10") [ fiber xdg ]
   ++ lib.optional (lib.versionAtLeast version "1.14.2") ocamlc-loc
-  ++ lib.optionals (lib.versionAtLeast version "1.17.0") [ astring camlp-streams merlin-lib ];
+  ++ lib.optionals (lib.versionAtLeast version "1.17.0") [ astring camlp-streams merlin-lib ]
+  ++ lib.optional (lib.versionAtLeast version "1.18.0") base
+  ;
 
   nativeBuildInputs = [ makeWrapper ];
 
diff --git a/pkgs/development/ocaml-modules/ocaml-lsp/jsonrpc.nix b/pkgs/development/ocaml-modules/ocaml-lsp/jsonrpc.nix
index aee22a26bd18..f2b650137e79 100644
--- a/pkgs/development/ocaml-modules/ocaml-lsp/jsonrpc.nix
+++ b/pkgs/development/ocaml-modules/ocaml-lsp/jsonrpc.nix
@@ -9,7 +9,7 @@
 , ocaml
 , version ?
     if lib.versionAtLeast ocaml.version "4.14" then
-      "1.17.0"
+      "1.18.0"
     else if lib.versionAtLeast ocaml.version "4.13" then
       "1.10.5"
     else if lib.versionAtLeast ocaml.version "4.12" then
@@ -19,6 +19,11 @@
 }:
 
 let params = {
+  "1.18.0" = {
+    name = "lsp";
+    minimalOCamlVersion = "4.14";
+    sha256 = "sha256-tZ2kPM/S/9J3yeX2laDjnHLA144b8svy9iwae32nXwM=";
+  };
   "1.17.0" = {
     name = "lsp";
     minimalOCamlVersion = "4.14";
@@ -54,7 +59,6 @@ buildDunePackage rec {
     inherit (params) sha256;
   };
 
-  duneVersion = "3";
   inherit (params) minimalOCamlVersion;
 
   buildInputs =
diff --git a/pkgs/development/ocaml-modules/ocaml-lsp/lsp.nix b/pkgs/development/ocaml-modules/ocaml-lsp/lsp.nix
index f06c425c4362..c77d1ed40453 100644
--- a/pkgs/development/ocaml-modules/ocaml-lsp/lsp.nix
+++ b/pkgs/development/ocaml-modules/ocaml-lsp/lsp.nix
@@ -23,7 +23,7 @@
 , ocaml
 , version ?
     if lib.versionAtLeast ocaml.version "4.14" then
-      "1.17.0"
+      "1.18.0"
     else if lib.versionAtLeast ocaml.version "4.13" then
       "1.10.5"
     else if lib.versionAtLeast ocaml.version "4.12" then
@@ -38,7 +38,6 @@ let jsonrpc_v = jsonrpc.override {
 buildDunePackage rec {
   pname = "lsp";
   inherit (jsonrpc_v) version src;
-  duneVersion = "3";
   minimalOCamlVersion =
     if lib.versionAtLeast version "1.7.0" then
       "4.12"