diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -2,11 +2,12 @@
 
 [MPI](https://www.mpi-forum.org) bindings for Haskell
 
-* [<img alt="Github" src="share/GitHub_Logo.png" height="25"
-  align="middle">](https://github.com/eschnett/mpi-hs)
-* [[Hackage]](http://hackage.haskell.org/package/mpi-hs) Haskell
+* [GitHub](https://github.com/eschnett/mpi-hs): Source code repository
+* [Hackage](http://hackage.haskell.org/package/mpi-hs): Haskell
   package and documentation
-* [![CircleCI](https://circleci.com/gh/eschnett/mpi-hs.svg?style=svg)](https://circleci.com/gh/eschnett/mpi-hs)
+* [CircleCI](https://circleci.com/gh/eschnett/mpi-hs): Continuous
+  integration
+  [![CircleCI](https://circleci.com/gh/eschnett/mpi-hs.svg?style=svg)](https://circleci.com/gh/eschnett/mpi-hs)
 
 
 
diff --git a/mpi-hs.cabal b/mpi-hs.cabal
--- a/mpi-hs.cabal
+++ b/mpi-hs.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 51db71059fcdd89fa4df2f6b20866b5abb0c7a517f8fe02a9d9687bb1139aa86
+-- hash: 2892e584ed19468e7f909cfad89e55d2e462d95a62b97faba37aa84634bfa800
 
 name:           mpi-hs
-version:        0.5.1.1
+version:        0.5.1.2
 synopsis:       MPI bindings for Haskell
 description:    MPI (the [Message Passing Interface](https://www.mpi-forum.org)) is
                 widely used standard for distributed-memory programming on HPC (High
@@ -69,10 +69,19 @@
   ghc-options: -Wall
   include-dirs:
       c/include
+      /usr/lib/x86_64-linux-gnu/openmpi/include
+      /opt/local/include/openmpi-mp
+      /usr/lib/openmpi/include
   c-sources:
       c/src/mpihs.c
+  extra-lib-dirs:
+      /usr/lib/x86_64-linux-gnu/openmpi/lib
+      /opt/local/lib/openmpi-mp
+      /usr/lib/openmpi/lib
   extra-libraries:
       mpi
+  build-tools:
+      c2hs
   build-depends:
       base >=4 && <5
     , binary
@@ -80,8 +89,6 @@
     , cereal
     , monad-loops
     , store
-  build-tools:
-      c2hs
   default-language: Haskell2010
 
 executable example
diff --git a/package.yaml b/package.yaml
--- a/package.yaml
+++ b/package.yaml
@@ -1,5 +1,5 @@
 name: mpi-hs
-version: '0.5.1.1'
+version: '0.5.1.2'
 github: "eschnett/mpi-hs"
 license: Apache-2.0
 author: "Erik Schnetter <schnetter@gmail.com>"
@@ -61,6 +61,13 @@
     - c/src/mpihs.c
   include-dirs:
     - c/include
+    - /usr/lib/x86_64-linux-gnu/openmpi/include # Debian
+    - /opt/local/include/openmpi-mp             # MacPorts
+    - /usr/lib/openmpi/include                  # Ubuntu
+  extra-lib-dirs:
+    - /usr/lib/x86_64-linux-gnu/openmpi/lib # Debian
+    - /opt/local/lib/openmpi-mp             # MacPorts
+    - /usr/lib/openmpi/lib                  # Ubuntu
   extra-libraries:
     - mpi
 
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,19 +1,6 @@
 # Resolver to choose a 'specific' stackage snapshot or a compiler version.
-resolver: lts-13.4
+resolver: lts-13.7
 
 # User packages to be built.
 packages:
   - .
-
-# extra-deps:
-#   - packman-0.5.0
-
-# Extra directories used by stack for building
-extra-include-dirs:
-  - /opt/local/include/openmpi-mp             # MacPorts
-  - /usr/lib/openmpi/include                  # Ubuntu
-  - /usr/lib/x86_64-linux-gnu/openmpi/include # Debian
-extra-lib-dirs:
-  - /opt/local/lib/openmpi-mp
-  - /usr/lib/openmpi/lib
-  - /usr/lib/x86_64-linux-gnu/openmpi/lib