diff --git a/pkgs/development/ocaml-modules/tar/default.nix b/pkgs/development/ocaml-modules/tar/default.nix
index 031bd4d5b141..3a21fd21a0c3 100644
--- a/pkgs/development/ocaml-modules/tar/default.nix
+++ b/pkgs/development/ocaml-modules/tar/default.nix
@@ -2,20 +2,18 @@
 , fetchurl
 , buildDunePackage
 , camlp-streams
-, ppx_cstruct
 , cstruct
 , decompress
 }:
 
 buildDunePackage rec {
   pname = "tar";
-  version = "2.2.2";
+  version = "2.5.1";
   src = fetchurl {
     url = "https://github.com/mirage/ocaml-tar/releases/download/v${version}/tar-${version}.tbz";
-    hash = "sha256-Q+41LPFZFHi9sXKFV3F13FZZNO3KXRSElEmr+nH58Uw=";
+    hash = "sha256-00QPSIZnoFvhZEnDcdEDJUqhE0uKLxNMM2pUE8aMPfQ=";
   };
 
-  duneVersion = "3";
   minimalOCamlVersion = "4.08";
 
   propagatedBuildInputs = [
@@ -24,10 +22,6 @@ buildDunePackage rec {
     decompress
   ];
 
-  buildInputs = [
-    ppx_cstruct
-  ];
-
   doCheck = true;
 
   meta = {
diff --git a/pkgs/development/ocaml-modules/tar/unix.nix b/pkgs/development/ocaml-modules/tar/unix.nix
index 9426a6aaf10f..92b5a9237f5d 100644
--- a/pkgs/development/ocaml-modules/tar/unix.nix
+++ b/pkgs/development/ocaml-modules/tar/unix.nix
@@ -3,12 +3,12 @@
 , tar
 , cstruct-lwt
 , lwt
+, git
 }:
 
 buildDunePackage rec {
   pname = "tar-unix";
   inherit (tar) version src doCheck;
-  duneVersion = "3";
 
   propagatedBuildInputs = [
     tar
@@ -16,6 +16,10 @@ buildDunePackage rec {
     lwt
   ];
 
+  nativeCheckInputs = [
+    git
+  ];
+
   meta = tar.meta // {
     description = "Decode and encode tar format files from Unix";
   };
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 64e3e12d7dba..85bf5a0f8160 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -1693,7 +1693,9 @@ let
 
     tar = callPackage ../development/ocaml-modules/tar { };
 
-    tar-unix = callPackage ../development/ocaml-modules/tar/unix.nix { };
+    tar-unix = callPackage ../development/ocaml-modules/tar/unix.nix {
+      inherit (pkgs) git;
+    };
 
     tcpip = callPackage ../development/ocaml-modules/tcpip { };