diff --git a/pkgs/development/ocaml-modules/visitors/default.nix b/pkgs/development/ocaml-modules/visitors/default.nix
new file mode 100644
index 000000000000..506721f7bf5e
--- /dev/null
+++ b/pkgs/development/ocaml-modules/visitors/default.nix
@@ -0,0 +1,23 @@
+{ stdenv, fetchurl, ocaml, findlib, ocamlbuild, cppo, ppx_tools, ppx_deriving, result }:
+
+stdenv.mkDerivation {
+  name = "ocaml${ocaml.version}-visitors-20171124";
+
+  src = fetchurl {
+    url = http://gallium.inria.fr/~fpottier/visitors/visitors-20171124.tar.gz;
+    sha256 = "04047k2v0pgwcdkgw7jk4955pgil0nj2ji0zfhmlqrdbinyfqzac";
+  };
+
+  buildInputs = [ ocaml findlib ocamlbuild cppo ];
+  propagatedBuildInputs = [ ppx_tools ppx_deriving result ];
+
+  createFindlibDestdir = true;
+
+  meta = with stdenv.lib; {
+    homepage = https://gitlab.inria.fr/fpottier/visitors;
+    license = licenses.lgpl21;
+    description = "An OCaml syntax extension (technically, a ppx_deriving plugin) which generates object-oriented visitors for traversing and transforming data structures";
+    inherit (ocaml.meta) platforms;
+    maintainers = [ maintainers.marsam ];
+  };
+}
diff --git a/pkgs/development/tools/analysis/flow/default.nix b/pkgs/development/tools/analysis/flow/default.nix
index 00b129706284..3d7a8abf4fe6 100644
--- a/pkgs/development/tools/analysis/flow/default.nix
+++ b/pkgs/development/tools/analysis/flow/default.nix
@@ -1,33 +1,28 @@
-{ stdenv, fetchFromGitHub, lib, ocamlPackages, libelf, cf-private, CoreServices }:
-
-with lib;
+{ stdenv, fetchFromGitHub, ocamlPackages, cf-private, CoreServices }:
 
 stdenv.mkDerivation rec {
-  version = "0.80.0";
+  version = "0.85.0";
   name = "flow-${version}";
 
   src = fetchFromGitHub {
-    owner = "facebook";
-    repo = "flow";
-    rev = "v${version}";
-    sha256 = "0jixisimqwbr46gh9357ya0rscv46svm6kqnawkq1shlf9nwa3lx";
+    owner  = "facebook";
+    repo   = "flow";
+    rev    = "refs/tags/v${version}";
+    sha256 = "0kci017bl4ihq89zpwlgdlwzv7kili8146940kyar5v66kgf7xsh";
   };
 
   installPhase = ''
-    mkdir -p $out/bin
-    cp bin/flow $out/bin/
+    install -Dm755 -t $out/bin bin/flow
   '';
 
-  buildInputs = [ libelf
-  ] ++ (with ocamlPackages; [
-    ocaml findlib camlp4 sedlex ocamlbuild lwt_ppx ppx_deriving ppx_gen_rec lwt_log wtf8 dtoa
-  ]) ++ optionals stdenv.isDarwin [ cf-private CoreServices ];
+  buildInputs = (with ocamlPackages; [ ocaml findlib ocamlbuild dtoa core_kernel sedlex ocaml_lwt lwt_log lwt_ppx ppx_deriving ppx_gen_rec ppx_tools_versioned visitors wtf8 ])
+    ++ stdenv.lib.optionals stdenv.isDarwin [ cf-private CoreServices ];
 
   meta = with stdenv.lib; {
     description = "A static type checker for JavaScript";
-    homepage = http://flowtype.org;
-    license = licenses.bsd3;
-    platforms = [ "x86_64-linux" "x86_64-darwin" ];
+    homepage = https://flow.org/;
+    license = licenses.mit;
+    platforms = ocamlPackages.ocaml.meta.platforms;
     maintainers = with maintainers; [ puffnfresh globin ];
   };
 }
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index b95ca0e0ef45..1d0c14914362 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -737,6 +737,8 @@ let
 
     vg = callPackage ../development/ocaml-modules/vg { };
 
+    visitors = callPackage ../development/ocaml-modules/visitors { };
+
     wasm = callPackage ../development/ocaml-modules/wasm { };
 
     wtf8 = callPackage ../development/ocaml-modules/wtf8 { };