diff --git a/pkgs/development/ocaml-modules/irmin/mem.nix b/pkgs/development/ocaml-modules/irmin/mem.nix
new file mode 100644
index 00000000000..b7040b9db0d
--- /dev/null
+++ b/pkgs/development/ocaml-modules/irmin/mem.nix
@@ -0,0 +1,19 @@
+{ lib, buildDunePackage, irmin, irmin-test }:
+
+buildDunePackage rec {
+
+  pname = "irmin-mem";
+
+  inherit (irmin) version src;
+
+  propagatedBuildInputs = [ irmin ];
+
+  checkInputs = lib.optional doCheck irmin-test;
+
+  doCheck = true;
+
+  meta = irmin.meta // {
+    description = "Generic in-memory Irmin stores";
+  };
+
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 96234d7436c..6f7fa3f7e56 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -372,6 +372,8 @@ let
 
     irmin = callPackage ../development/ocaml-modules/irmin { };
 
+    irmin-mem = callPackage ../development/ocaml-modules/irmin/mem.nix { };
+
     irmin-test = callPackage ../development/ocaml-modules/irmin/test.nix { };
 
     jingoo = callPackage ../development/ocaml-modules/jingoo {