diff --git a/.gitignore b/.gitignore
index df76606..c80ca94 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1 @@
-/ocplib-simplex-0.3.tar.gz
+/ocplib-simplex-*.tar.gz
diff --git a/ocaml-ocplib-simplex-destdir.patch b/ocaml-ocplib-simplex-destdir.patch
new file mode 100644
index 0000000..c3a05ea
--- /dev/null
+++ b/ocaml-ocplib-simplex-destdir.patch
@@ -0,0 +1,35 @@
+--- Makefile.in.orig	2017-08-23 06:49:52.000000000 -0600
++++ Makefile.in	2019-05-27 21:11:10.304632260 -0600
+@@ -13,11 +13,12 @@
+ # (enclosed in the file LGPL).
+ 
+ # where to install the binaries
+-DESTDIR=@prefix@
+-# prefix=@prefix@
++
++prefix=@prefix@
++libdir=@libdir@
+ # exec_prefix=@exec_prefix@
+ # BINDIR=$(DESTDIR)@bindir@
+-LIBDIR=$(DESTDIR)/lib/
++LIBDIR=$(prefix)$(libdir)
+ # DATADIR=$(DESTDIR)@datadir@/ocplib-simplex
+ 
+ # where to install the man page
+@@ -112,12 +113,14 @@ META: config.status
+ ##############
+ 
+ install: all META
+-	OCAMLFIND_DESTDIR=$(LIBDIR) \
++	mkdir -p $(DESTDIR)$(LIBDIR)
++	OCAMLFIND_DESTDIR=$(DESTDIR)$(LIBDIR) \
+ 	  ocamlfind install ocplib-simplex src/$(LIBNAME).* src/*.mli META
+ 
+ 
+ uninstall:
+-	ocamlfind remove ocplib-simplex
++	OCAMLFIND_DESTDIR=$(DESTDIR)$(LIBDIR) \
++	  ocamlfind remove ocplib-simplex
+ 
+ # generic rules
+ ###############
diff --git a/ocaml-ocplib-simplex-tests.patch b/ocaml-ocplib-simplex-tests.patch
new file mode 100644
index 0000000..ff2ac7b
--- /dev/null
+++ b/ocaml-ocplib-simplex-tests.patch
@@ -0,0 +1,38 @@
+--- tests/standalone_minimal_maximization.ml.orig	2017-08-23 06:49:52.000000000 -0600
++++ tests/standalone_minimal_maximization.ml	2019-05-27 21:09:08.353940039 -0600
+@@ -97,10 +97,11 @@ let () =
+   *)
+ 
+   (* x <= 5 *)
+-  let sim = Sim.Assert.var sim "x" three (Ex.singleton "x>=3") None Ex.empty in
++  let sim, _ =
++    Sim.Assert.var sim "x" three (Ex.singleton "x>=3") None Ex.empty in
+ 
+   (* s == x + y <= 10 *)
+-  let sim =
++  let sim, _ =
+     Sim.Assert.poly sim x_y "s" None Ex.empty ten (Ex.singleton "x+y<=10") in
+ 
+   aux sim x_y;
+--- tests/standalone_minimal.ml.orig	2017-08-23 06:49:52.000000000 -0600
++++ tests/standalone_minimal.ml	2019-05-27 21:08:36.913019394 -0600
+@@ -63,14 +63,16 @@ let () =
+   let m_one = Some (Rat.m_one, Rat.zero) in
+ 
+   (* x >= 0 *)
+-  let sim = Sim.Assert.var sim "x" zero (Ex.singleton "x>=0") None Ex.empty in
++  let sim, _ =
++    Sim.Assert.var sim "x" zero (Ex.singleton "x>=0") None Ex.empty in
+ 
+   (* y >= 0 *)
+-  let sim = Sim.Assert.var sim "y" zero (Ex.singleton "y>=0") None Ex.empty in
++  let sim, _ =
++    Sim.Assert.var sim "y" zero (Ex.singleton "y>=0") None Ex.empty in
+   let x_y = Sim.Core.P.from_list ["x", Rat.one; "y", Rat.one] in
+ 
+   (* z == x + y <= -1 *)
+-  let sim =
++  let sim, _ =
+     Sim.Assert.poly sim x_y "z" None Ex.empty m_one (Ex.singleton "x+y<=-1") in
+   let sim = Sim.Solve.solve sim in
+   match Sim.Result.get None sim with
diff --git a/ocaml-ocplib-simplex.spec b/ocaml-ocplib-simplex.spec
index d5665ab..9a4bba0 100644
--- a/ocaml-ocplib-simplex.spec
+++ b/ocaml-ocplib-simplex.spec
@@ -1,19 +1,22 @@
-%global opt %(test -x %{_bindir}/ocamlopt && echo 1 || echo 0)
-%if !%{opt}
+%ifnarch %{ocaml_native_compiler}
 %global debug_package %{nil}
 %endif
 
 %global pkgname ocplib-simplex
 
 Name:           ocaml-%{pkgname}
-Version:        0.3
-Release:        15%{?dist}
+Version:        0.4
+Release:        1%{?dist}
 Summary:        Simplex algorithm for solving systems of linear inequalities
 
 # The same exception to clause 6 as provided by ocaml applies to this package.
 License:        LGPLv2 with exceptions
 URL:            https://github.com/OCamlPro-Iguernlala/ocplib-simplex
-Source0:        https://github.com/OCamlPro-Iguernlala/%{pkgname}/archive/%{version}/%{pkgname}-%{version}.tar.gz
+Source0:        https://github.com/OCamlPro-Iguernlala/%{pkgname}/archive/v%{version}/%{pkgname}-%{version}.tar.gz
+# Upstream patch to fix the tests
+Patch0:         %{name}-tests.patch
+# Upstream patch to fix DESTDIR
+Patch1:         %{name}-destdir.patch
 
 BuildRequires:  autoconf
 BuildRequires:  ocaml
@@ -34,12 +37,15 @@ The %{name}-devel package contains libraries and signature
 files for developing applications that use %{name}.
 
 %prep
-%autosetup -n %{pkgname}-%{version}
+%autosetup -p0 -n %{pkgname}-%{version}
 autoconf
 
+# Upstream's attempt to set OCAMLFIND_DESTDIR interferes with ours
+sed -i '/OCAMLFIND_DESTDIR/d' Makefile.in
+
 %build
 %configure
-%if %opt
+%ifarch %{ocaml_native_compiler}
 make %{?_smp_mflags} opt
 %else
 make %{?_smp_mflags} byte
@@ -58,7 +64,7 @@ make local-tests
 %doc README.md
 %license LICENSE
 %{_libdir}/ocaml/%{pkgname}/
-%if %opt
+%ifarch %{ocaml_native_compiler}
 %exclude %{_libdir}/ocaml/*/*.a
 %exclude %{_libdir}/ocaml/*/*.cmxa
 %exclude %{_libdir}/ocaml/*/*.cmx
@@ -67,7 +73,7 @@ make local-tests
 
 %files devel
 %doc extra/simplex_invariants.txt
-%if %opt
+%ifarch %{ocaml_native_compiler}
 %{_libdir}/ocaml/*/*.a
 %{_libdir}/ocaml/*/*.cmxa
 %{_libdir}/ocaml/*/*.cmx
@@ -75,6 +81,9 @@ make local-tests
 %{_libdir}/ocaml/*/*.mli
 
 %changelog
+* Wed Jun  5 2019 Jerry James <loganjerry@gmail.com> - 0.4-1
+- New upstream version
+
 * Mon Apr 29 2019 Richard W.M. Jones <rjones@redhat.com> - 0.3-15
 - OCaml 4.08.0 (beta 3) rebuild.
 
diff --git a/sources b/sources
index 612e3c1..81858ba 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-ef6d61360bc1ed6c6f273dd723c71016  ocplib-simplex-0.3.tar.gz
+SHA512 (ocplib-simplex-0.4.tar.gz) = 5eb80f0c8ad32291d24423255c0359e139cd85e2262b0cbbfaffcab66d9a7eb66c9bf04bb9d5d5c103574ec7041a72cde5412e6cb03fc9fe4a8fd257dab49a76