diff --git a/.gitignore b/.gitignore
index c1a2e77..20c1629 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ lwt-2.0.0+rc1.tar.gz
 /lwt-4.1.0.tar.gz
 /lwt-4.2.1.tar.gz
 /lwt-4.3.0.tar.gz
+/lwt-4.3.1.tar.gz
diff --git a/ocaml-lwt.spec b/ocaml-lwt.spec
index 50bbea5..761c0a5 100644
--- a/ocaml-lwt.spec
+++ b/ocaml-lwt.spec
@@ -1,5 +1,5 @@
 Name:           ocaml-lwt
-Version:        4.3.0
+Version:        4.3.1
 Release:        1%{?dist}
 Summary:        OCaml lightweight thread library
 
@@ -13,9 +13,13 @@ BuildRequires:  ocaml-ocamlbuild
 BuildRequires:  ocaml-findlib-devel
 
 BuildRequires:  dune
+BuildRequires:  ocaml-dune-devel
 BuildRequires:  ocaml-cppo
 BuildRequires:  ocaml-result-devel
+
+# lwt.unix dependencies
 BuildRequires:  ocaml-mmap-devel
+BuildRequires:  ocaml-ocplib-endian-devel
 
 # lwt_react dependencies.
 BuildRequires:  ocaml-react-devel
@@ -97,11 +101,14 @@ sed 's,test_mcast "mcast-join-noloop" true false;,(*test_mcast "mcast-join-noloo
 sed 's,test_mcast "mcast-nojoin-loop" false true;,(*test_mcast "mcast-nojoin-loop" false true;*),' -i test/unix/test_mcast.ml
 sed 's,test_mcast "mcast-nojoin-noloop" false false;,(*test_mcast "mcast-nojoin-noloop" false false;*),' -i test/unix/test_mcast.ml
 
+# Some lwt.unix tests fail because we can't seem to look up the
+# user/group name from inside koji. I guess that makes sense?
+# Those tests have guards not to run on win32; we can hack them to not run here either.
+sed 's,Sys.win32 && not is_wsl,Sys.unix,g' -i test/unix/test_lwt_unix.cppo.ml
 
 %build
 dune build --profile=release --verbose
 
-
 %install
 dune install --profile=release --destdir %{buildroot}
 
@@ -110,12 +117,10 @@ dune install --profile=release --destdir %{buildroot}
 # Remove spurious jbuilder-installed documentation.
 rm -rf %{buildroot}/%{_prefix}/doc
 
-
 %check
 # In LWT 4.2.1 / OCaml 4.08 the tests fail because it can't find
 # Ast_helper.  It seems like this might be a problem with LWT itself.
-#dune runtest --profile=release
-
+dune runtest --profile=release
 
 %files
 %doc CHANGES README.md
@@ -136,7 +141,7 @@ rm -rf %{buildroot}/%{_prefix}/doc
 %{_libdir}/ocaml/lwt/*.cmx
 %endif
 %{_libdir}/ocaml/lwt/*.mli
-#%{_libdir}/ocaml/stublibs/*.so
+%{_libdir}/ocaml/stublibs/*.so
 
 %files react
 %doc CHANGES README.md
@@ -178,6 +183,9 @@ rm -rf %{buildroot}/%{_prefix}/doc
 
 
 %changelog
+* Tue Oct 01 2019 Ben Rosser <rosser.bjr@gmail.com> - 4.3.1-1
+- Update to latest upstream release; reenable tests.
+
 * Wed Aug 21 2019 Richard W.M. Jones <rjones@redhat.com> - 4.3.0-1
 - New upstream version 4.3.0.
 - Remove patches from git which were unused and unapplied.
diff --git a/sources b/sources
index 514bb1f..6ac2ab8 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (lwt-4.3.0.tar.gz) = 8e66f5b2443b2cc2889cd3f425db6e7261165603f1c31f8800540900d944dc6ae99b5cf02a29244cfd40fa4b077f238a7a788ba970734faa47deec98b55ac252
+SHA512 (lwt-4.3.1.tar.gz) = ff5b2f69513bca07073a5562912ccb94f64c13799c083e9afdaa5e9a41a3b269e9dc4283a98cf4e45fff1275a500bfc1c5f407d155481de62dc07bc5987a9d89