diff --git a/.github/workflows/workflow.yml b/.github/workflows/workflow.yml
index b8e5368..6c0c740 100644
--- a/.github/workflows/workflow.yml
+++ b/.github/workflows/workflow.yml
@@ -54,16 +54,16 @@ jobs:
       - name: Build project
         run: opam exec -- dune build -p eigen
 
-      - name: Install openblas on windows
+      - name: Install openblas on windows (for testing owl)
         if: ${{ runner.os == 'Windows' }}
         run: |
           echo pwd
           git clone https://github.com/xianyi/OpenBLAS.git || true
           cd OpenBLAS
-          make CC=x86_64-w64-mingw32-gcc FC=x86_64-w64-mingw32-gfortran TARGET=HASWELL
-          make CC=x86_64-w64-mingw32-gcc FC=x86_64-w64-mingw32-gfortran TARGET=HASWELL PREFIX=/usr/x86_64-w64-mingw32/sys-root/mingw install
+          make CC=x86_64-w64-mingw32-gcc FC=x86_64-w64-mingw32-gfortran
+          make CC=x86_64-w64-mingw32-gcc FC=x86_64-w64-mingw32-gfortran PREFIX=/usr/x86_64-w64-mingw32/sys-root/mingw install
 
       - name: Build and test owl
         run: |
-          opam depext owl
-          opam install -t owl
+          opam depext owl owl-top owl-zoo
+          opam install -t owl owl-top owl-zoo
diff --git a/CHANGES b/CHANGES
new file mode 100644
index 0000000..b68a659
--- /dev/null
+++ b/CHANGES
@@ -0,0 +1,8 @@
+# 0.4.0 (12-11-2020)
+
+* Fix bug in linking cmxs files ([#27](https://github.com/owlbarn/eigen/issues/27) @nojb @nilsbecker @dbuenzli)
+
+# 0.3.0 (22-10-2020)
+
+* Release 0.3.0, windows compatibility (thanks to @kkirstein)
+
diff --git a/dune-project b/dune-project
index 305ab76..494ab9b 100644
--- a/dune-project
+++ b/dune-project
@@ -1,2 +1,3 @@
-(lang dune 2.0)
+(lang dune 2.8)
 (name eigen)
+(use_standard_c_and_cxx_flags true)
\ No newline at end of file
diff --git a/eigen.opam b/eigen.opam
index 4bb534a..1364b37 100644
--- a/eigen.opam
+++ b/eigen.opam
@@ -12,7 +12,7 @@ build: [
 depends: [
   "ocaml" {>= "4.02"}
   "ctypes" {>= "0.14.0"}
-  "dune" {>= "2.0.0"}
+  "dune" {>= "2.8.0"}
 ]
 synopsis: "Owl's OCaml interface to Eigen3 C++ library"
 description:
diff --git a/eigen/dune b/eigen/dune
index f8e1e56..f3d1cd4 100644
--- a/eigen/dune
+++ b/eigen/dune
@@ -33,12 +33,12 @@ let () = Printf.ksprintf Jbuild_plugin.V1.send {|
  (public_name eigen)
  (libraries ctypes)
  (modules :standard ffi_eigen_generated)
- (foreign_archives ../eigen_cpp/eigen_cpp_stubs)
+ (foreign_archives ../eigen_cpp/eigen_cpp)
  (foreign_stubs
   (language c)
   (names eigen_utils_stubs ffi_eigen_generated_stub)
   (include_dirs ../eigen_cpp/lib)
-  (flags :standard %s)
+  (flags :standard -lstdc++ -leigen_cpp %s)
   )
 )
 |} eigen_flags
diff --git a/eigen_cpp/dune b/eigen_cpp/dune
index b6ddf56..620c877 100644
--- a/eigen_cpp/dune
+++ b/eigen_cpp/dune
@@ -2,8 +2,7 @@
 
 let optflags =
   match Sys.getenv "EIGENCPP_OPTFLAGS" with
-  | s ->
-    s
+  | s -> s
   | exception Not_found ->
     "-Ofast -march=native -funroll-loops -ffast-math"
 
@@ -17,7 +16,7 @@ let () = Printf.ksprintf Jbuild_plugin.V1.send {|
 (include_subdirs unqualified)
 
 (foreign_library
- (archive_name eigen_cpp_stubs)
+ (archive_name eigen_cpp)
  (language cxx)
  (names eigen_tensor eigen_dsmat eigen_spmat)
  (include_dirs lib lib/unsupported)
@@ -29,6 +28,7 @@ let () = Printf.ksprintf Jbuild_plugin.V1.send {|
    -O3
    -std=c++11
    -lstdc++
+   -fno-threadsafe-statics
    %s
    %s
   )
diff --git a/eigen_cpp/eigen_cpp.ml b/eigen_cpp/eigen_cpp.ml
deleted file mode 100644
index 3c3a727..0000000
--- a/eigen_cpp/eigen_cpp.ml
+++ /dev/null
@@ -1 +0,0 @@
-let linkme = ()