diff --git a/pkgs/development/ocaml-modules/ocaml-protoc/default.nix b/pkgs/development/ocaml-modules/ocaml-protoc/default.nix
index 8d9d3a768209..79c9f37942da 100644
--- a/pkgs/development/ocaml-modules/ocaml-protoc/default.nix
+++ b/pkgs/development/ocaml-modules/ocaml-protoc/default.nix
@@ -1,7 +1,10 @@
 {
+  lib,
+  ocaml,
   buildDunePackage,
   pbrt,
   stdlib-shims,
+  pbrt_services,
 }:
 
 buildDunePackage {
@@ -12,7 +15,8 @@ buildDunePackage {
   buildInputs = [ stdlib-shims ];
   propagatedBuildInputs = [ pbrt ];
 
-  doCheck = true;
+  doCheck = lib.versionAtLeast ocaml.version "5.1";
+  checkInputs = [ pbrt_services ];
 
   meta = pbrt.meta // {
     description = "Protobuf Compiler for OCaml";
diff --git a/pkgs/development/ocaml-modules/pbrt/default.nix b/pkgs/development/ocaml-modules/pbrt/default.nix
index 10df7382f287..102916dad809 100644
--- a/pkgs/development/ocaml-modules/pbrt/default.nix
+++ b/pkgs/development/ocaml-modules/pbrt/default.nix
@@ -6,15 +6,13 @@
 
 buildDunePackage (finalAttrs: {
   pname = "pbrt";
-  version = "2.4";
-
-  minimalOCamlVersion = "4.03";
+  version = "4.1";
 
   src = fetchFromGitHub {
     owner = "mransan";
     repo = "ocaml-protoc";
-    rev = "${finalAttrs.version}.0";
-    hash = "sha256-EXugdcjALukSjB31zAVG9WiN6GMGXi2jlhHWaZ+p+uM=";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-UrgrzI5Pgi79C/OhqYxwSNfqsoBULUZ13XVaB71fGes=";
   };
 
   meta = {
diff --git a/pkgs/development/ocaml-modules/pbrt/services.nix b/pkgs/development/ocaml-modules/pbrt/services.nix
new file mode 100644
index 000000000000..1d02a4a657ba
--- /dev/null
+++ b/pkgs/development/ocaml-modules/pbrt/services.nix
@@ -0,0 +1,19 @@
+{
+  buildDunePackage,
+  pbrt,
+  pbrt_yojson,
+}:
+
+buildDunePackage {
+  pname = "pbrt_services";
+  inherit (pbrt) version src;
+
+  propagatedBuildInputs = [
+    pbrt
+    pbrt_yojson
+  ];
+
+  meta = pbrt.meta // {
+    description = "Runtime library for ocaml-protoc to support RPC services";
+  };
+}
diff --git a/pkgs/development/ocaml-modules/pbrt/yojson.nix b/pkgs/development/ocaml-modules/pbrt/yojson.nix
new file mode 100644
index 000000000000..a352408b7503
--- /dev/null
+++ b/pkgs/development/ocaml-modules/pbrt/yojson.nix
@@ -0,0 +1,21 @@
+{
+  buildDunePackage,
+  pbrt,
+  base64,
+  yojson,
+}:
+
+buildDunePackage {
+  pname = "pbrt_yojson";
+  inherit (pbrt) version src;
+
+  propagatedBuildInputs = [
+    pbrt
+    base64
+    yojson
+  ];
+
+  meta = pbrt.meta // {
+    description = "Runtime library for ocaml-protoc to support JSON encoding/decoding";
+  };
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index a06a161d2c60..7e578f84b7b9 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -1713,6 +1713,10 @@ let
 
         pbrt = callPackage ../development/ocaml-modules/pbrt { };
 
+        pbrt_services = callPackage ../development/ocaml-modules/pbrt/services.nix { };
+
+        pbrt_yojson = callPackage ../development/ocaml-modules/pbrt/yojson.nix { };
+
         pcre2 = callPackage ../development/ocaml-modules/pcre2 {
           inherit (pkgs) pcre2;
         };