diff --git a/pkgs/development/ocaml-modules/wtf8/default.nix b/pkgs/development/ocaml-modules/wtf8/default.nix
new file mode 100644
index 000000000000..4cde95c0c4cc
--- /dev/null
+++ b/pkgs/development/ocaml-modules/wtf8/default.nix
@@ -0,0 +1,32 @@
+{ stdenv, fetchurl, ocaml, findlib, jbuilder }:
+
+assert stdenv.lib.versionAtLeast (stdenv.lib.getVersion ocaml) "4.01";
+
+stdenv.mkDerivation rec {
+  pname = "wtf8";
+  name = "ocaml-${pname}-${version}";
+  version = "1.0.1";
+
+  src = fetchurl {
+    url = "https://github.com/flowtype/ocaml-${pname}/releases/download/v${version}/${pname}-${version}.tbz";
+    sha256 = "1msg3vycd3k8qqj61sc23qks541cxpb97vrnrvrhjnqxsqnh6ygq";
+  };
+
+  unpackCmd = "tar xjf $src";
+
+  buildInputs = [ ocaml findlib jbuilder ];
+
+  buildPhase = "jbuilder build -p wtf8";
+
+  inherit (jbuilder) installPhase;
+
+  createFindLibDestdir = true;
+
+  meta = with stdenv.lib; {
+    homepage = https://github.com/flowtype/ocaml-wtf8;
+    description = "WTF-8 is a superset of UTF-8 that allows unpaired surrogates.";
+    license = licenses.mit;
+    platforms = ocaml.meta.platforms or [];
+    maintainers = [ maintainers.eqyiel ];
+  };
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index b74f9009aece..4a7c77172cc0 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -681,6 +681,8 @@ let
 
     wasm = callPackage ../development/ocaml-modules/wasm { };
 
+    wtf8 = callPackage ../development/ocaml-modules/wtf8 { };
+
     x509 = callPackage ../development/ocaml-modules/x509 { };
 
     xmlm = callPackage ../development/ocaml-modules/xmlm { };