diff --git a/pkgs/development/ocaml-modules/irmin-watcher/default.nix b/pkgs/development/ocaml-modules/irmin-watcher/default.nix
new file mode 100644
index 00000000000..55dc9ca866b
--- /dev/null
+++ b/pkgs/development/ocaml-modules/irmin-watcher/default.nix
@@ -0,0 +1,23 @@
+{ lib, fetchurl, buildDunePackage
+, astring, fmt, logs, ocaml_lwt
+}:
+
+buildDunePackage rec {
+  pname = "irmin-watcher";
+  version = "0.4.1";
+
+  src = fetchurl {
+    url = "https://github.com/mirage/irmin-watcher/releases/download/${version}/irmin-watcher-${version}.tbz";
+    sha256 = "00d4ph4jbsw6adp3zqdrwi099hfcf7p1xzi0685qr7bgcmandjfv";
+  };
+
+  propagatedBuildInputs = [ astring fmt logs ocaml_lwt ];
+
+  meta = {
+    homepage = "https://github.com/mirage/irmin-watcher";
+    description = "Portable Irmin watch backends using FSevents or Inotify";
+    license = lib.licenses.isc;
+    maintainers = [ lib.maintainers.vbgl ];
+  };
+
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index df821a643de..a2f81341ec8 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -386,6 +386,8 @@ let
 
     irmin-test = callPackage ../development/ocaml-modules/irmin/test.nix { };
 
+    irmin-watcher = callPackage ../development/ocaml-modules/irmin-watcher { };
+
     jingoo = callPackage ../development/ocaml-modules/jingoo {
       pcre = ocaml_pcre;
     };