diff --git a/pkgs/development/ocaml-modules/wasm/default.nix b/pkgs/development/ocaml-modules/wasm/default.nix
new file mode 100644
index 00000000000..03ea4a29330
--- /dev/null
+++ b/pkgs/development/ocaml-modules/wasm/default.nix
@@ -0,0 +1,31 @@
+{ stdenv, fetchFromGitHub, ocaml, findlib, ocamlbuild }:
+
+if !stdenv.lib.versionAtLeast ocaml.version "4.02"
+then throw "wasm is not available for OCaml ${ocaml.version}"
+else
+
+stdenv.mkDerivation rec {
+  name = "ocaml${ocaml.version}-wasm-${version}";
+  version = "0.13";
+
+  src = fetchFromGitHub {
+    owner = "WebAssembly";
+    repo = "spec";
+    rev = "v${version}";
+    sha256 = "0l67w1dmhgzrhmw3pw2w35h54imax0zdpa9yyqppzzbagxgn87kn";
+  };
+
+  buildInputs = [ ocaml findlib ocamlbuild ];
+
+  makeFlags = [ "-C" "interpreter" ];
+
+  createFindlibDestdir = true;
+
+  meta = {
+    description = "An OCaml library to read and write Web Assembly (wasm) files and manipulate their AST";
+    license = stdenv.lib.licenses.asl20;
+    maintainers = [ stdenv.lib.maintainers.vbgl ];
+    inherit (src.meta) homepage;
+    inherit (ocaml.meta) platforms;
+  };
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index a50f996b7cc..492b22c0552 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -612,6 +612,8 @@ let
 
     vg = callPackage ../development/ocaml-modules/vg { };
 
+    wasm = callPackage ../development/ocaml-modules/wasm { };
+
     x509 = callPackage ../development/ocaml-modules/x509 { };
 
     xmlm = callPackage ../development/ocaml-modules/xmlm { };