diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 4284765e..564fe979 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -5,8 +5,9 @@ on:
     branches: [ master ]
   pull_request:
     branches: [ master ]
-  schedule:
-    - cron: "0 0 * * *"
+# don't run the CRON part in my fork
+#  schedule:
+#    - cron: "0 0 * * *"
 
   workflow_dispatch:
 
diff --git a/.github/workflows/run_cmake.yaml b/.github/workflows/run_cmake.yaml
new file mode 100644
index 00000000..76d7d94f
--- /dev/null
+++ b/.github/workflows/run_cmake.yaml
@@ -0,0 +1,83 @@
+# This workflow carries out the build of the package with CMake
+
+name: CMake build
+
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  build-GNU:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install gfortran libopenmpi-dev cmake python3-dev pip
+          pip install scipy matplotlib getdist anesthetic ipython mpi4py
+
+      - name: Run CMake
+        run: cmake -B build
+
+      - name: Build
+        run: make -C build install
+
+      - name: Test pypolychord
+        run: python run_pypolychord.py
+
+      - name: Test pypolychord (MPI)
+        run: mpirun -np 2 python run_pypolychord.py
+
+  build-Intel:
+    runs-on: ubuntu-latest
+    container:
+      image: intel/oneapi-hpckit
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Run CMake
+        run: cmake -B build -DCMAKE_Fortran_COMPILER=ifort -DCMAKE_CXX_COMPILER=icpc
+
+      - name: Build
+        run: make -C build install
+
+      - name: Test pypolychord
+        run: python run_pypolychord.py
+
+      - name: Test pypolychord (MPI)
+        run: mpirun -np 2 python run_pypolychord.py
+
+  build-MacOS:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        cc: [ gcc, clang ]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install dependencies
+        run: |
+          brew install cmake gcc openmpi
+          pip3 install numpy scipy matplotlib getdist anesthetic ipython mpi4py
+
+      - name: Run CMake - GCC
+        if: ${{ env.cc == 'gcc' }}
+        run: cmake -B build -DCMAKE_Fortran_COMPILER=gfortran-11 -DCMAKE_CXX_COMPILER=gcc-11
+
+      - name: Run CMake - AppleClang
+        if: ${{ env.cc == 'clang' }}
+        run: cmake -B build -DCMAKE_Fortran_COMPILER=gfortran-11
+
+      - name: Build
+        run: make -C build install
+
+      - name: Test pypolychord
+        run: python run_pypolychord.py
+
+      - name: Test pypolychord (MPI)
+        run: mpirun -np 2 python run_pypolychord.py
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 00000000..9ef355e7
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,145 @@
+cmake_minimum_required(VERSION 3.4)
+
+project(PolyChordLite Fortran)
+
+# languages
+enable_language(CXX)
+enable_language(Fortran)
+
+# options
+option(MPI "Build with MPI" ON)
+option(python "Build PyPolyChord package" ON)
+option(python_user_install "Install Python package for user (--user)" ON)
+
+# enforce matching of the CXX and Fortran compilers
+if (NOT "${CMAKE_Fortran_COMPILER_ID}" MATCHES "${CMAKE_CXX_COMPILER_ID}"
+        AND NOT ("${CMAKE_Fortran_COMPILER_ID}" MATCHES "GNU" AND
+        "${CMAKE_CXX_COMPILER_ID}" MATCHES "AppleClang"))
+    message(FATAL_ERROR "You need to use the same vendor for your C++ and Fortran compiler")
+endif ()
+
+# flags for all three compiler types
+# todo: inspect the flags and implement in a nicer way
+if ("${CMAKE_Fortran_COMPILER_ID}" MATCHES "Intel")
+    message("Using INTEL compilers")
+
+    set(CMAKE_Fortran_FLAGS "-fpp -fpic -assume noold_maxminloc -heap-arrays -ipo -O3 -no-prec-div -xHost -w -vec-report0 -qopt-report0")
+    set(CMAKE_CXX_FLAGS "-std=c++11 -fpic -ipo -O3 -no-prec-div -xHost -w -vec-report0 -qopt-report0")
+
+    add_compile_options("-nofor-main")
+    link_libraries("-nofor-main")
+
+elseif ("${CMAKE_Fortran_COMPILER_ID}" MATCHES "GNU")
+    message("Using GNU compilers")
+
+    set(CMAKE_Fortran_FLAGS "-ffree-line-length-none -cpp -fPIC -fno-stack-arrays -Ofast")
+    set(CMAKE_CXX_FLAGS "-std=c++11 -fPIC -Ofast")
+
+    # for GitHub actions MacOS -- debug only
+    add_compile_options("-lstdc++")
+    link_libraries("-lstdc++")
+
+    if (CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER 10.0)
+        # GCC 10 is complaining about MPI interfaces, turn this to warnings
+        SET(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -fallow-argument-mismatch")
+    endif ()
+
+elseif ("${CMAKE_Fortran_COMPILER_ID}" MATCHES "Cray")
+    message("Using Cray compilers")
+
+    set(CMAKE_Fortran_FLAGS "-fpp -fpic -qopenmp -dynamic")
+    set(CMAKE_CXX_FLAGS "-fpic -qopenmp -dynamic")
+
+endif ()
+
+# find MPI & link to everything from now on
+if (MPI)
+    find_package(MPI REQUIRED)
+    message(STATUS "MPI_Fortran_COMPILER: ${MPI_Fortran_COMPILER}")
+    link_libraries(MPI::MPI_Fortran)
+    link_libraries(MPI::MPI_CXX)
+
+    # definitions
+    add_compile_definitions(USE_MPI)
+endif (MPI)
+
+# this will be module building directory, allows linking
+set(CMAKE_Fortran_MODULE_DIRECTORY ${PROJECT_BINARY_DIR}/generated/mods)
+
+# on installation we get this prefix as well
+set(CMAKE_INSTALL_PREFIX ${PROJECT_BINARY_DIR})
+
+# target directories -> stuff installed in these directories
+set(target_lib_dir ${PROJECT_SOURCE_DIR}/lib)
+set(target_bin_dir ${PROJECT_SOURCE_DIR}/bin)
+
+# directories where we want to make things
+add_subdirectory(src)
+add_subdirectory(likelihoods)
+
+if (python)
+    #################################################################
+    # The Compiled .so file
+    #################################################################
+
+    # PyPolyChord stuff
+    message(STATUS "Enabling Python package build")
+    find_package(Python3 COMPONENTS Interpreter Development NumPy REQUIRED)
+
+    # find out the suffix for the current python version
+    EXECUTE_PROCESS(
+            COMMAND ${Python3_EXECUTABLE} "-c" "import sysconfig;print(sysconfig.get_config_var('EXT_SUFFIX'))"
+            OUTPUT_VARIABLE python_so_suffix
+    )
+    STRING(REPLACE "\n" "" python_so_suffix ${python_so_suffix})
+    message(STATUS "Python shared object suffix is: ${python_so_suffix}")
+
+    # the extension module
+    add_library(_pypolychord SHARED pypolychord/_pypolychord.cpp $<TARGET_OBJECTS:objlib_chord>)
+    set_target_properties(_pypolychord
+            PROPERTIES
+            OUTPUT_NAME _pypolychord
+            PREFIX ""
+            SUFFIX "${python_so_suffix}"
+            )
+    # dependencies and includes
+    target_link_libraries(_pypolychord Python3::Python Python3::NumPy)
+    target_include_directories(_pypolychord PUBLIC src/polychord) # PolyChord headers for python extensions
+
+    # remember the place of this
+    set(target_python_so ${CMAKE_CURRENT_BINARY_DIR}/_pypolychord${python_so_suffix})
+
+    # place all outputs in one place
+    install(TARGETS _pypolychord
+            LIBRARY DESTINATION ${target_lib_dir})
+
+    #################################################################
+    # The simple python module
+    #################################################################
+
+    # hack ofr version
+    set(PACKAGE_VERSION "1.18.2")
+
+    set(SETUP_PY_IN "${CMAKE_CURRENT_SOURCE_DIR}/setup_cmake_template.py")
+    set(SETUP_PY "${CMAKE_CURRENT_BINARY_DIR}/setup.py")
+    set(DEPS "${CMAKE_CURRENT_SOURCE_DIR}/pypolychord/__init__.py")
+    set(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/build/timestamp") # dummy target for dependence
+
+    # fill in the variables of the setup.py file
+    configure_file(${SETUP_PY_IN} ${SETUP_PY})
+
+    # custom target
+    add_custom_command(OUTPUT ${OUTPUT}
+            COMMAND ${Python3_EXECUTABLE} ${SETUP_PY} build
+            COMMAND ${CMAKE_COMMAND} -E touch ${OUTPUT}
+            DEPENDS ${DEPS} _pypolychord)
+    add_custom_target(target ALL DEPENDS ${OUTPUT})
+
+    # installation with setup.py
+    if (python_user_install)
+        install(CODE "execute_process(COMMAND ${Python3_EXECUTABLE} ${SETUP_PY} install)")
+    else (python_user_install)
+        install(CODE "execute_process(COMMAND ${Python3_EXECUTABLE} ${SETUP_PY} install --user)")
+    endif (python_user_install)
+
+endif (python)
diff --git a/Makefile b/Makefile
index 8e871ce0..107448bf 100644
--- a/Makefile
+++ b/Makefile
@@ -44,7 +44,7 @@ endif
 
 
 ifeq ($(MPI),1)
-FFLAGS += -DMPI
+FFLAGS += -DUSE_MPI
 CXXFLAGS += -DUSE_MPI
 endif
 
diff --git a/README.rst b/README.rst
index 363f72da..d88147f8 100644
--- a/README.rst
+++ b/README.rst
@@ -5,8 +5,7 @@
    :target: https://arxiv.org/abs/1506.00171
    :alt: Open-access paper
 
-PolyChord v 1.20.1
-
+PolyChord v 1.21.0
 Will Handley, Mike Hobson & Anthony Lasenby
 
 wh260@mrao.cam.ac.uk
diff --git a/devtools/docker_gnu/Dockerfile b/devtools/docker_gnu/Dockerfile
new file mode 100644
index 00000000..3f6881b1
--- /dev/null
+++ b/devtools/docker_gnu/Dockerfile
@@ -0,0 +1,40 @@
+FROM ubuntu:latest
+MAINTAINER "Tamas K Stenczel <tks@polychord.co.uk>"
+
+# Time Zone data
+ARG DEBIAN_FRONTEND=noninteractive
+ENV TZ=Europe/London
+
+RUN apt-get -q update && \
+    apt-get -qy install --no-install-recommends \
+        # general
+        make \
+        gfortran \
+        libopenmpi-dev \
+        libblas-dev \
+        liblapack-dev \
+        libfftw3-3  \
+        # cmake and tools
+        cmake vim git wget ca-certificates \
+        g++ \
+        python3-dev pip \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN pip3 install scipy matplotlib getdist anesthetic ipython mpi4py
+
+# reinstall newer cmake, same as in the Intel image
+ARG cmake_url=https://github.com/Kitware/CMake/releases/download/v3.20.0/cmake-3.20.0-linux-x86_64.sh
+ADD $cmake_url /
+RUN file=$(basename "$cmake_url") && \
+   bash $file --prefix=/usr --skip-license && \
+   rm $file
+
+# DEV use: oh-my-zsh instead of bash
+# Uses "robbyrussell" theme (original Oh My Zsh theme), with no plugins
+RUN sh -c "$(wget -O- https://github.com/deluan/zsh-in-docker/releases/download/v1.1.1/zsh-in-docker.sh)" -- \
+    -t robbyrussell
+ENTRYPOINT "/usr/bin/zsh"
+WORKDIR /work
+
+# python executable
+RUN echo "alias python=python3" >> /root/.zshrc
diff --git a/devtools/docker_intel/Dockerfile b/devtools/docker_intel/Dockerfile
new file mode 100644
index 00000000..8c9ee817
--- /dev/null
+++ b/devtools/docker_intel/Dockerfile
@@ -0,0 +1,107 @@
+FROM intel/oneapi:os-tools-ubuntu18.04
+MAINTAINER "Tamas K Stenczel <tks@polychord.co.uk>"
+
+# Time Zone data
+ARG DEBIAN_FRONTEND=noninteractive
+ARG APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1
+ENV TZ=Europe/London
+
+#############################################################
+# Assembled from Intel Base-Kit and HPC-Kit Dockerfiles
+#   includes my additions of apt packages
+#############################################################
+# install Intel(R) oneAPI Base Toolkit
+RUN apt-get update -y && \
+apt-get install -y --no-install-recommends -o=Dpkg::Use-Pty=0 \
+    # Intel compilers and MPI library
+    intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic \
+    intel-oneapi-mpi-devel \
+    intel-oneapi-compiler-fortran \
+    intel-oneapi-python python3-pip \
+    # other tools and libraries
+    libblas-dev \
+    liblapack-dev \
+    cmake \
+    make \
+    vim git wget ca-certificates \
+--
+
+RUN pip3 install scipy matplotlib getdist anesthetic ipython mpi4py
+
+# reinstall newer cmake
+ARG cmake_url=https://github.com/Kitware/CMake/releases/download/v3.20.0/cmake-3.20.0-linux-x86_64.sh
+ADD $cmake_url /
+RUN file=$(basename "$cmake_url") && \
+    bash $file --prefix=/usr --skip-license && \
+    rm $file
+
+# from Intel HPC toolkit
+# setvars.sh environment variables
+ENV ACL_BOARD_VENDOR_PATH='/opt/Intel/OpenCLFPGA/oneAPI/Boards'
+ENV ADVISOR_2021_DIR='/opt/intel/oneapi/advisor/2021.3.0'
+ENV APM='/opt/intel/oneapi/advisor/2021.3.0/perfmodels'
+ENV CCL_CONFIGURATION='cpu_gpu_dpcpp'
+ENV CCL_ROOT='/opt/intel/oneapi/ccl/2021.3.0'
+ENV CLASSPATH='/opt/intel/oneapi/mpi/2021.3.0//lib/mpi.jar:/opt/intel/oneapi/dal/2021.3.0/lib/onedal.jar'
+ENV CLCK_ROOT='/opt/intel/oneapi/clck/2021.3.0'
+ENV CMAKE_PREFIX_PATH='/opt/intel/oneapi/vpl/2021.4.0:/opt/intel/oneapi/tbb/2021.3.0/env/..:/opt/intel/oneapi/dal/2021.3.0'
+ENV CMPLR_ROOT='/opt/intel/oneapi/compiler/2021.3.0'
+ENV CONDA_DEFAULT_ENV='intelpython-python3.7'
+ENV CONDA_EXE='/opt/intel/oneapi/intelpython/latest/bin/conda'
+ENV CONDA_PREFIX='/opt/intel/oneapi/intelpython/latest'
+ENV CONDA_PROMPT_MODIFIER='(intelpython-python3.7) '
+ENV CONDA_PYTHON_EXE='/opt/intel/oneapi/intelpython/latest/bin/python'
+ENV CONDA_SHLVL='1'
+ENV CPATH='/opt/intel/oneapi/vpl/2021.4.0/include:/opt/intel/oneapi/tbb/2021.3.0/env/../include:/opt/intel/oneapi/mpi/2021.3.0//include:/opt/intel/oneapi/mkl/2021.3.0/include:/opt/intel/oneapi/ippcp/2021.3.0/include:/opt/intel/oneapi/ipp/2021.3.0/include:/opt/intel/oneapi/dpl/2021.4.0/linux/include:/opt/intel/oneapi/dnnl/2021.3.0/cpu_dpcpp_gpu_dpcpp/lib:/opt/intel/oneapi/dev-utilities/2021.3.0/include:/opt/intel/oneapi/dal/2021.3.0/include:/opt/intel/oneapi/compiler/2021.3.0/linux/include:/opt/intel/oneapi/ccl/2021.3.0/include/cpu_gpu_dpcpp'
+ENV CPLUS_INCLUDE_PATH='/opt/intel/oneapi/clck/2021.3.0/include'
+ENV DAALROOT='/opt/intel/oneapi/dal/2021.3.0'
+ENV DALROOT='/opt/intel/oneapi/dal/2021.3.0'
+ENV DAL_MAJOR_BINARY='1'
+ENV DAL_MINOR_BINARY='1'
+ENV DNNLROOT='/opt/intel/oneapi/dnnl/2021.3.0/cpu_dpcpp_gpu_dpcpp'
+ENV DPL_ROOT='/opt/intel/oneapi/dpl/2021.4.0'
+ENV FI_PROVIDER_PATH='/opt/intel/oneapi/mpi/2021.3.0//libfabric/lib/prov:/usr/lib64/libfabric'
+ENV FPGA_VARS_ARGS=''
+ENV FPGA_VARS_DIR='/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga'
+ENV INFOPATH='/opt/intel/oneapi/debugger/10.1.2/gdb/intel64/lib'
+ENV INSPECTOR_2021_DIR='/opt/intel/oneapi/inspector/2021.3.0'
+ENV INTELFPGAOCLSDKROOT='/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga'
+ENV INTEL_LICENSE_FILE='/opt/intel/licenses:/root/intel/licenses:/opt/intel/oneapi/clck/2021.3.0/licensing:/opt/intel/licenses:/root/intel/licenses:/Users/Shared/Library/Application Support/Intel/Licenses'
+ENV INTEL_PYTHONHOME='/opt/intel/oneapi/debugger/10.1.2/dep'
+ENV IPPCP_TARGET_ARCH='intel64'
+ENV IPPCRYPTOROOT='/opt/intel/oneapi/ippcp/2021.3.0'
+ENV IPPROOT='/opt/intel/oneapi/ipp/2021.3.0'
+ENV IPP_TARGET_ARCH='intel64'
+ENV I_MPI_ROOT='/opt/intel/oneapi/mpi/2021.3.0'
+ENV LD_LIBRARY_PATH='/opt/intel/oneapi/vpl/2021.4.0/lib:/opt/intel/oneapi/tbb/2021.3.0/env/../lib/intel64/gcc4.8:/opt/intel/oneapi/mpi/2021.3.0//libfabric/lib:/opt/intel/oneapi/mpi/2021.3.0//lib/release:/opt/intel/oneapi/mpi/2021.3.0//lib:/opt/intel/oneapi/mkl/2021.3.0/lib/intel64:/opt/intel/oneapi/itac/2021.3.0/slib:/opt/intel/oneapi/ippcp/2021.3.0/lib/intel64:/opt/intel/oneapi/ipp/2021.3.0/lib/intel64:/opt/intel/oneapi/dnnl/2021.3.0/cpu_dpcpp_gpu_dpcpp/lib:/opt/intel/oneapi/debugger/10.1.2/gdb/intel64/lib:/opt/intel/oneapi/debugger/10.1.2/libipt/intel64/lib:/opt/intel/oneapi/debugger/10.1.2/dep/lib:/opt/intel/oneapi/dal/2021.3.0/lib/intel64:/opt/intel/oneapi/compiler/2021.3.0/linux/lib:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/x64:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/emu:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga/host/linux64/lib:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga/linux64/lib:/opt/intel/oneapi/compiler/2021.3.0/linux/compiler/lib/intel64_lin:/opt/intel/oneapi/ccl/2021.3.0/lib/cpu_gpu_dpcpp'
+ENV LIBRARY_PATH='/opt/intel/oneapi/vpl/2021.4.0/lib:/opt/intel/oneapi/tbb/2021.3.0/env/../lib/intel64/gcc4.8:/opt/intel/oneapi/mpi/2021.3.0//libfabric/lib:/opt/intel/oneapi/mpi/2021.3.0//lib/release:/opt/intel/oneapi/mpi/2021.3.0//lib:/opt/intel/oneapi/mkl/2021.3.0/lib/intel64:/opt/intel/oneapi/ippcp/2021.3.0/lib/intel64:/opt/intel/oneapi/ipp/2021.3.0/lib/intel64:/opt/intel/oneapi/dnnl/2021.3.0/cpu_dpcpp_gpu_dpcpp/lib:/opt/intel/oneapi/dal/2021.3.0/lib/intel64:/opt/intel/oneapi/compiler/2021.3.0/linux/compiler/lib/intel64_lin:/opt/intel/oneapi/compiler/2021.3.0/linux/lib:/opt/intel/oneapi/clck/2021.3.0/lib/intel64:/opt/intel/oneapi/ccl/2021.3.0/lib/cpu_gpu_dpcpp'
+ENV MANPATH='/opt/intel/oneapi/mpi/2021.3.0/man:/opt/intel/oneapi/itac/2021.3.0/man:/opt/intel/oneapi/debugger/10.1.2/documentation/man:/opt/intel/oneapi/compiler/2021.3.0/documentation/en/man/common:/opt/intel/oneapi/clck/2021.3.0/man::'
+ENV MKLROOT='/opt/intel/oneapi/mkl/2021.3.0'
+ENV NLSPATH='/opt/intel/oneapi/mkl/2021.3.0/lib/intel64/locale/%l_%t/%N'
+ENV OCL_ICD_FILENAMES='libintelocl_emu.so:libalteracl.so:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/x64/libintelocl.so'
+ENV ONEAPI_ROOT='/opt/intel/oneapi'
+ENV PATH='/opt/intel/oneapi/vtune/2021.5.0/bin64:/opt/intel/oneapi/vpl/2021.4.0/bin:/opt/intel/oneapi/mpi/2021.3.0//libfabric/bin:/opt/intel/oneapi/mpi/2021.3.0//bin:/opt/intel/oneapi/mkl/2021.3.0/bin/intel64:/opt/intel/oneapi/itac/2021.3.0/bin:/opt/intel/oneapi/intelpython/latest/bin:/opt/intel/oneapi/intelpython/latest/condabin:/opt/intel/oneapi/inspector/2021.3.0/bin64:/opt/intel/oneapi/dev-utilities/2021.3.0/bin:/opt/intel/oneapi/debugger/10.1.2/gdb/intel64/bin:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga/llvm/aocl-bin:/opt/intel/oneapi/compiler/2021.3.0/linux/lib/oclfpga/bin:/opt/intel/oneapi/compiler/2021.3.0/linux/bin/intel64:/opt/intel/oneapi/compiler/2021.3.0/linux/bin:/opt/intel/oneapi/clck/2021.3.0/bin/intel64:/opt/intel/oneapi/advisor/2021.3.0/bin64:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'
+ENV PKG_CONFIG_PATH='/opt/intel/oneapi/vtune/2021.5.0/include/pkgconfig/lib64:/opt/intel/oneapi/vpl/2021.4.0/lib/pkgconfig:/opt/intel/oneapi/mkl/2021.3.0/tools/pkgconfig:/opt/intel/oneapi/inspector/2021.3.0/include/pkgconfig/lib64:/opt/intel/oneapi/advisor/2021.3.0/include/pkgconfig/lib64:'
+ENV PYTHONPATH='/opt/intel/oneapi/advisor/2021.3.0/pythonapi'
+ENV SETVARS_COMPLETED='1'
+ENV SETVARS_VARS_PATH='/opt/intel/oneapi/vtune/latest/env/vars.sh'
+ENV TBBROOT='/opt/intel/oneapi/tbb/2021.3.0/env/..'
+ENV VTUNE_PROFILER_2021_DIR='/opt/intel/oneapi/vtune/2021.5.0'
+ENV VT_ADD_LIBS='-ldwarf -lelf -lvtunwind -lm -lpthread'
+ENV VT_LIB_DIR='/opt/intel/oneapi/itac/2021.3.0/lib'
+ENV VT_MPI='impi4'
+ENV VT_ROOT='/opt/intel/oneapi/itac/2021.3.0'
+ENV VT_SLIB_DIR='/opt/intel/oneapi/itac/2021.3.0/slib'
+ENV _CE_CONDA=''
+ENV _CE_M=''
+
+
+#############################################################
+# Entrypoint & ZSH
+#############################################################
+# DEV use: oh-my-zsh instead of bash
+RUN sh -c "$(wget -O- https://github.com/deluan/zsh-in-docker/releases/download/v1.1.1/zsh-in-docker.sh)" -- \
+    -t dallas
+ENTRYPOINT "/usr/bin/zsh"
+WORKDIR /work
+
diff --git a/likelihoods/CMakeLists.txt b/likelihoods/CMakeLists.txt
new file mode 100644
index 00000000..0de4fee7
--- /dev/null
+++ b/likelihoods/CMakeLists.txt
@@ -0,0 +1,4 @@
+project(likelyhoods)
+
+# only include the tree
+add_subdirectory(examples)
\ No newline at end of file
diff --git a/likelihoods/examples/CMakeLists.txt b/likelihoods/examples/CMakeLists.txt
new file mode 100644
index 00000000..cdbac61d
--- /dev/null
+++ b/likelihoods/examples/CMakeLists.txt
@@ -0,0 +1,41 @@
+project(examples Fortran)
+
+# parse each example separately
+file(GLOB ${PROJECT_NAME}_sources "*.f90" "*.F90")
+set(${PROJECT_NAME}_library_list "") # hold all the targets we make
+foreach (filename ${${PROJECT_NAME}_sources})
+    # strip the file name
+    get_filename_component(archive_name ${filename} NAME_WE)
+
+    if (${archive_name} STREQUAL "polychord_examples")
+        # make sure this is not turned into an object & executable alone
+        continue()
+    endif ()
+
+    # compile once into object -> use in lib and exec as well
+    add_library(objlib_${archive_name} OBJECT ${filename})
+    set_target_properties(objlib_${archive_name} PROPERTIES POSITION_INDEPENDENT_CODE 1 LINKER_LANGUAGE Fortran)
+    target_link_libraries(objlib_${archive_name} chord)
+
+    # static library
+    add_library(${archive_name} STATIC $<TARGET_OBJECTS:objlib_${archive_name}>)
+
+    # executable + linking, uses the program and one of the likelihood implementations
+    add_executable(${archive_name}_exec $<TARGET_OBJECTS:objlib_${archive_name}> polychord_examples.f90)
+    target_link_libraries(${archive_name}_exec chord) # link libchoord.a to it
+    set_target_properties(${archive_name}_exec PROPERTIES OUTPUT_NAME ${archive_name} CLEAN_DIRECT_OUTPUT 1 LINKER_LANGUAGE Fortran)
+
+    # add to target list
+    list(APPEND ${PROJECT_NAME}_library_list ${archive_name})
+    list(APPEND ${PROJECT_NAME}_library_list ${archive_name}_exec)
+
+    # tell the user
+    message("Adding example: ${archive_name} (from ${filename})")
+endforeach ()
+
+
+# standard: where to put the targets
+install(TARGETS ${${PROJECT_NAME}_library_list}
+        RUNTIME DESTINATION ${target_bin_dir}
+        LIBRARY DESTINATION ${target_lib_dir}
+        ARCHIVE DESTINATION ${target_lib_dir})
diff --git a/likelihoods/examples/polychord_examples.f90 b/likelihoods/examples/polychord_examples.f90
new file mode 100644
index 00000000..49ad93e1
--- /dev/null
+++ b/likelihoods/examples/polychord_examples.f90
@@ -0,0 +1,23 @@
+!> This is the main driving routine of the nested sampling algorithm
+! TKS: copied from src/drivers for the CMake build system, only kept there to not break the old build system
+program PolyChord
+
+    ! ~~~~~~~ Loaded Modules ~~~~~~~
+    use interfaces_module,        only: run_polychord
+    use loglikelihood_module,     only: loglikelihood, setup_loglikelihood
+    use utils_module,             only: STR_LENGTH
+    use abort_module,             only: halt_program
+
+    ! ~~~~~~~ Local Variable Declaration ~~~~~~~
+    implicit none
+    character(len=STR_LENGTH)                 :: input_file     ! input file
+
+    if(iargc()==1) then
+        call getarg(1,input_file) 
+    else
+        call halt_program('PolyChord should be called with at most one argument, the input file')
+    end if
+
+    call run_polychord(loglikelihood, setup_loglikelihood, input_file)
+
+end program PolyChord
diff --git a/likelihoods/examples/random_gaussian.f90 b/likelihoods/examples/random_gaussian.f90
index c54584ac..6efc0fd5 100644
--- a/likelihoods/examples/random_gaussian.f90
+++ b/likelihoods/examples/random_gaussian.f90
@@ -32,7 +32,7 @@ end function loglikelihood
 
 
     subroutine setup_loglikelihood(settings)
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module
 #endif
         use settings_module,   only: program_settings
@@ -54,7 +54,7 @@ subroutine setup_loglikelihood(settings)
         ! Generate a random covariance matrix, its inverse and logdet on the root node
         call random_inverse_covmat(invcovmat,logdetcovmat,sigma,nDims)
 
-#ifdef MPI
+#ifdef USE_MPI
         call initialise_mpi(settings%feedback)
         ! Broadcast the covariance matrix and normalisation data to the
         ! rest of the nodes
diff --git a/pypolychord/__init__.py b/pypolychord/__init__.py
index 3e4047d7..7c6e3ddb 100644
--- a/pypolychord/__init__.py
+++ b/pypolychord/__init__.py
@@ -1,3 +1,3 @@
-__version__ = "1.20.1"
+__version__ = "1.21.0"
 from pypolychord.settings import PolyChordSettings
 from pypolychord.polychord import run_polychord
diff --git a/setup_cmake_template.py b/setup_cmake_template.py
new file mode 100644
index 00000000..6380f289
--- /dev/null
+++ b/setup_cmake_template.py
@@ -0,0 +1,79 @@
+"""
+Template for setup.py that should be populated by CMake with:
+configure_file(${SETUP_PY_IN} ${SETUP_PY})
+
+Used template variables:
+    - "target_python_so" : place where _pypolychord.ARCH.so is built (NOT install path)
+    - "PACKAGE_VERSION" : version of the package
+    - "CMAKE_CURRENT_SOURCE_DIR": root directory, where a standard setup.py would be placed
+"""
+
+import os
+import shutil
+import sys
+from distutils.core import setup
+
+from setuptools import Extension
+from setuptools.command.build_ext import build_ext
+
+
+def readme():
+    with open('${CMAKE_CURRENT_SOURCE_DIR}/README.rst') as f:
+        return f.read()
+
+
+class MyBuildExtension(build_ext):
+    """This class 'builds' the extension module, by
+    copying it from the place where CMake placed it.
+    """
+
+    def build_extension(self, ext):
+
+        # _pypolychord.ARCH.so
+        if os.path.exists("${target_python_so}"):
+            shutil.copyfile("${target_python_so}", self.get_ext_fullpath(ext.name))
+        elif sys.argv[2] == "install":
+            # let's warn here, though this should not happen with the current CMake setup
+            print("NOT FOUND: ${target_python_so}\nYour installation may be incomplete.")
+
+
+setup(name='pypolychord',
+      description='Python interface to PolyChord ${PACKAGE_VERSION}',
+      long_description=readme(),
+      long_description_content_type='text/x-rst',
+      url='https://ccpforge.cse.rl.ac.uk/gf/project/polychord/',
+      author='Will Handley',
+      author_email='wh260@cam.ac.uk',
+      license='PolyChord',
+      install_requires=['numpy', 'scipy'],
+      extras_require={'plotting': 'getdist'},
+
+      classifiers=[
+          "Development Status :: 5 - Production/Stable",
+
+          "Intended Audience :: Education",
+
+          "Operating System :: MacOS :: MacOS X",
+          "Operating System :: Unix",
+
+          "Topic :: Scientific/Engineering :: Astronomy",
+          "Topic :: Scientific/Engineering :: Physics",
+
+          "Programming Language :: C++",
+          "Programming Language :: Fortran",
+          'Programming Language :: Python :: 3',
+          'Programming Language :: Python :: 3.6',
+          'Programming Language :: Python :: 3.7',
+          'Programming Language :: Python :: 3.8',
+          'Programming Language :: Python :: 3.9',
+          "Programming Language :: Python :: 3.10",
+
+      ],
+
+      # Don't touch anything below here - CMake fills this in
+      version='${PACKAGE_VERSION}',
+      package_dir={'pypolychord': '${CMAKE_CURRENT_SOURCE_DIR}/pypolychord'},
+      packages=['pypolychord'],
+      cmdclass={'build_ext': MyBuildExtension},
+      ext_modules=[Extension('_pypolychord', [])],
+      )
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 00000000..bdcecba5
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,5 @@
+project(src)
+
+# only include the tree
+add_subdirectory(polychord)
+add_subdirectory(drivers)
\ No newline at end of file
diff --git a/src/drivers/CMakeLists.txt b/src/drivers/CMakeLists.txt
new file mode 100644
index 00000000..21b618a8
--- /dev/null
+++ b/src/drivers/CMakeLists.txt
@@ -0,0 +1 @@
+project(polychord_examples)
diff --git a/src/drivers/polychord_examples.f90 b/src/drivers/polychord_examples.f90
index 40c6149d..bf88d7c8 100644
--- a/src/drivers/polychord_examples.f90
+++ b/src/drivers/polychord_examples.f90
@@ -1,4 +1,6 @@
 !> This is the main driving routine of the nested sampling algorithm
+! TKS: this was relocated to likelihoods/examples for the CMake build system.
+!      delete here when the Makefiles are updated or outdated
 program PolyChord
 
     ! ~~~~~~~ Loaded Modules ~~~~~~~
diff --git a/src/polychord/CMakeLists.txt b/src/polychord/CMakeLists.txt
new file mode 100644
index 00000000..fc26af5e
--- /dev/null
+++ b/src/polychord/CMakeLists.txt
@@ -0,0 +1,27 @@
+project(chord Fortran)
+
+# file glob -> sources -> object -> static & shared lib as well
+file(GLOB ${PROJECT_NAME}_sources "*.f90" "*.F90" "*.cpp")
+message(STATUS "Sources for project ${PROJECT_NAME}: ${${PROJECT_NAME}_sources}")
+
+# this is the "object library" target: compiles the sources only once
+add_library(objlib_${PROJECT_NAME} OBJECT ${${PROJECT_NAME}_sources})
+
+# shared libraries need PIC
+set_property(TARGET objlib_${PROJECT_NAME} PROPERTY POSITION_INDEPENDENT_CODE 1)
+
+# libcoord.a
+add_library(${PROJECT_NAME} STATIC $<TARGET_OBJECTS:objlib_${PROJECT_NAME}>)
+set_property(TARGET ${PROJECT_NAME} PROPERTY LINKER_LANGUAGE Fortran)
+
+# libcoord.so as well -> needs a different target name, but the same lib name
+add_library(${PROJECT_NAME}_shared SHARED $<TARGET_OBJECTS:objlib_${PROJECT_NAME}>)
+set_target_properties(${PROJECT_NAME}_shared
+        PROPERTIES
+        OUTPUT_NAME ${PROJECT_NAME}
+        CLEAN_DIRECT_OUTPUT 1
+        LINKER_LANGUAGE Fortran)
+
+# standard: where to put the targets
+install(TARGETS ${PROJECT_NAME} ${PROJECT_NAME}_shared
+        LIBRARY DESTINATION ${target_lib_dir})
diff --git a/src/polychord/abort.F90 b/src/polychord/abort.F90
index fda69985..7cd49946 100644
--- a/src/polychord/abort.F90
+++ b/src/polychord/abort.F90
@@ -5,13 +5,13 @@ module abort_module
     subroutine halt_program(message)
         use utils_module, only: stderr_unit
         implicit none
-#ifdef MPI
+#ifdef USE_MPI
         include 'mpif.h'
 #endif
 
         character(LEN=*), intent(in), optional :: message
 
-#ifdef MPI
+#ifdef USE_MPI
         integer :: errorcode=1
         integer :: mpierror
 #endif
@@ -22,7 +22,7 @@ subroutine halt_program(message)
             write(stderr_unit,'( 20("=") )')
         end if 
 
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_ABORT(MPI_COMM_WORLD,errorcode,mpierror)
 #else
         stop 1
diff --git a/src/polychord/feedback.f90 b/src/polychord/feedback.f90
index 090d4639..8c8e4596 100644
--- a/src/polychord/feedback.f90
+++ b/src/polychord/feedback.f90
@@ -28,7 +28,7 @@ subroutine write_opening_statement(settings)
             write(stdout_unit,'("")')
             write(stdout_unit,'("PolyChord: Next Generation Nested Sampling")')
             write(stdout_unit,'("copyright: Will Handley, Mike Hobson & Anthony Lasenby")')
-            write(stdout_unit,'("  version: 1.20.1")')
+            write(stdout_unit,'("  version: 1.21.0")')
             write(stdout_unit,'("  release: 1st June 2021")')
             write(stdout_unit,'("    email: wh260@mrao.cam.ac.uk")')
             write(stdout_unit,'("")')
diff --git a/src/polychord/generate.F90 b/src/polychord/generate.F90
index 8adf0fb3..23d37f7f 100644
--- a/src/polychord/generate.F90
+++ b/src/polychord/generate.F90
@@ -68,7 +68,7 @@ subroutine GenerateLivePoints(loglikelihood,prior,settings,RTI,mpi_information)
         use run_time_module,   only: run_time_info,initialise_run_time_info, find_min_loglikelihoods
         use array_module,     only: add_point
         use abort_module
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module, only: mpi_bundle,is_root,linear_mode,throw_point,catch_point,more_points_needed,sum_integers,sum_doubles,request_point,no_more_points
 #else
         use mpi_module, only: mpi_bundle,is_root,linear_mode
@@ -100,7 +100,7 @@ function prior(cube) result(theta)
         type(run_time_info) :: RTI
 
         type(mpi_bundle),intent(in) :: mpi_information
-#ifdef MPI
+#ifdef USE_MPI
         integer             :: active_workers    !  Number of currently working workers
         integer             :: worker_id         !  Worker identifier to signal who to throw back to
 #endif
@@ -181,7 +181,7 @@ function prior(cube) result(theta)
             end do
 
 
-#ifdef MPI
+#ifdef USE_MPI
         else 
             !===================== PARALLEL MODE =======================
 
@@ -246,7 +246,7 @@ function prior(cube) result(theta)
 #endif
         end if !(nprocs case)
 
-#ifdef MPI
+#ifdef USE_MPI
         nlike = sum_integers(nlike,mpi_information) ! Gather the likelihood calls onto one node
         ndiscarded = sum_integers(ndiscarded,mpi_information) ! Gather the likelihood calls onto one node
         total_time = sum_doubles(total_time,mpi_information) ! Sum up the total time taken
@@ -319,7 +319,7 @@ subroutine time_speeds(loglikelihood,prior,settings,RTI,speed,mpi_information)
         use utils_module,    only: normal_fb,stdout_unit,fancy_fb,time
         use calculate_module, only: calculate_point
         use abort_module
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module, only: mpi_bundle,is_root,sum_doubles,sum_integers
 #else
         use mpi_module, only: mpi_bundle,is_root
@@ -419,7 +419,7 @@ function prior(cube) result(theta)
                 end if
 
             end do
-#ifdef MPI
+#ifdef USE_MPI
             total_time=sum_doubles(total_time,mpi_information)
             i_live = sum_integers(i_live,mpi_information)
             nlike = sum_integers(nlike,mpi_information)
@@ -450,7 +450,7 @@ subroutine GenerateLivePointsFromSeed(loglikelihood,prior,settings,RTI,mpi_infor
         use array_module,     only: add_point
         use abort_module
         use chordal_module, only: slice_sample
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module, only: mpi_bundle,is_root,linear_mode,throw_point,catch_point,more_points_needed,sum_integers,sum_doubles,request_point,no_more_points
 #else
         use mpi_module, only: mpi_bundle,is_root,linear_mode
@@ -482,7 +482,7 @@ function prior(cube) result(theta)
         type(run_time_info) :: RTI
 
         type(mpi_bundle),intent(in) :: mpi_information
-#ifdef MPI
+#ifdef USE_MPI
         integer             :: active_workers    !  Number of currently working workers
         integer             :: worker_id         !  Worker identifier to signal who to throw back to
 #endif
@@ -559,7 +559,7 @@ function prior(cube) result(theta)
 
             end do
 
-#ifdef MPI
+#ifdef USE_MPI
         else 
             !===================== PARALLEL MODE =======================
 
@@ -629,7 +629,7 @@ function prior(cube) result(theta)
 #endif
         end if !(nprocs case)
 
-#ifdef MPI
+#ifdef USE_MPI
         do i_grade=1,size(settings%grade_dims)
             nlikes(i_grade) = sum_integers(nlikes(i_grade),mpi_information) ! Gather the likelihood calls onto one node
             times(i_grade) = sum_doubles(times(i_grade),mpi_information) ! Sum up the total time taken
diff --git a/src/polychord/interfaces.F90 b/src/polychord/interfaces.F90
index ac3fe110..1f654d92 100644
--- a/src/polychord/interfaces.F90
+++ b/src/polychord/interfaces.F90
@@ -2,7 +2,7 @@
 module interfaces_module
     use utils_module, only: dp
     implicit none
-#ifdef MPI
+#ifdef USE_MPI
     include 'mpif.h'
 #endif
     interface run_polychord
@@ -16,11 +16,11 @@ subroutine run_polychord_full(loglikelihood, prior_transform, dumper, settings_i
         use settings_module,          only: program_settings,initialise_settings
         use random_module,            only: initialise_random
         use nested_sampling_module,   only: NestedSampling
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module,               only: initialise_mpi, finalise_mpi
 #endif
         implicit none
-#ifdef MPI
+#ifdef USE_MPI
         include 'mpif.h'
 #endif
 
@@ -56,7 +56,7 @@ end subroutine dumper
 
         real(dp), dimension(4) :: output_info
 
-#ifdef MPI
+#ifdef USE_MPI
         if (present(mpi_communicator)) then
             comm = mpi_communicator
         else 
@@ -73,7 +73,7 @@ end subroutine dumper
         end if
         settings = settings_in
         call initialise_settings(settings)   
-#ifdef MPI
+#ifdef USE_MPI
         output_info = NestedSampling(loglikelihood,prior_transform,dumper,settings,comm) 
         call finalise_mpi
 #else
@@ -105,7 +105,7 @@ end subroutine dumper
         type(program_settings),intent(in)    :: settings  ! The program settings 
         integer, intent(in), optional :: mpi_communicator
         integer :: comm
-#ifdef MPI
+#ifdef USE_MPI
         if (present(mpi_communicator)) then
             comm = mpi_communicator
         else 
@@ -145,7 +145,7 @@ end function prior_transform
         type(program_settings),intent(in)    :: settings  ! The program settings 
         integer, intent(in), optional :: mpi_communicator
         integer :: comm
-#ifdef MPI
+#ifdef USE_MPI
         if (present(mpi_communicator)) then
             comm = mpi_communicator
         else 
@@ -177,7 +177,7 @@ end function loglikelihood
         !> MPI handle
         integer, intent(in), optional :: mpi_communicator
         integer :: comm
-#ifdef MPI
+#ifdef USE_MPI
         if (present(mpi_communicator)) then
             comm = mpi_communicator
         else 
@@ -231,7 +231,7 @@ end subroutine setup_loglikelihood
         end interface
         integer, intent(in), optional :: mpi_communicator
         integer :: comm
-#ifdef MPI
+#ifdef USE_MPI
         if (present(mpi_communicator)) then
             comm = mpi_communicator
         else 
diff --git a/src/polychord/maximiser.F90 b/src/polychord/maximiser.F90
index bf949e7b..f2990220 100644
--- a/src/polychord/maximiser.F90
+++ b/src/polychord/maximiser.F90
@@ -11,7 +11,7 @@ subroutine maximise(loglikelihood,prior,settings,RTI)
         use run_time_module,   only: run_time_info
         use read_write_module,   only: write_max_file, mean
         use chordal_module, only: generate_nhats, slice_sample
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module, only: mpi_bundle,is_root, throw_point, catch_point, mpi_synchronise, throw_seed, catch_seed
 #else
         use mpi_module, only: mpi_bundle,is_root
@@ -70,7 +70,7 @@ function do_maximisation(loglikelihood,prior,settings,RTI, posterior) result(max
         use read_write_module,   only: write_max_file, mean
         use chordal_module, only: generate_nhats, slice_sample
         use nelder_mead_module, only: nelder_mead
-#ifdef MPI
+#ifdef USE_MPI
         use mpi_module, only: mpi_bundle,is_root, throw_point, catch_point, mpi_synchronise, throw_seed, catch_seed
 #else
         use mpi_module, only: mpi_bundle,is_root
diff --git a/src/polychord/mpi_utils.F90 b/src/polychord/mpi_utils.F90
index 9a891b2a..813cf89d 100644
--- a/src/polychord/mpi_utils.F90
+++ b/src/polychord/mpi_utils.F90
@@ -2,7 +2,7 @@ module mpi_module
     use utils_module, only: dp, normal_fb
 
     implicit none
-#ifdef MPI
+#ifdef USE_MPI
     include 'mpif.h'
 #endif
 
@@ -83,7 +83,7 @@ function get_nprocs(mpi_communicator) result(nprocs)
         integer, intent(in) :: mpi_communicator
         integer :: nprocs
 
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_COMM_SIZE(  & 
             mpi_communicator,&!handle
             nprocs,          &!return number of processors
@@ -103,7 +103,7 @@ function get_rank(mpi_communicator) result(myrank)
         integer, intent(in) :: mpi_communicator
         integer :: myrank
 
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_COMM_RANK(  & 
             mpi_communicator,&!handle
             myrank,          &!return rank of calling processor 
@@ -132,7 +132,7 @@ function get_root(mpi_communicator) result(root)
         ! Get the rank of the process
         myrank = get_rank(mpi_communicator)
 
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_ALLREDUCE(  &
             myrank,          &!send buffer 
             root,            &!recieve buffer
@@ -149,7 +149,7 @@ function get_root(mpi_communicator) result(root)
     end function get_root
 
 
-#ifdef MPI
+#ifdef USE_MPI
     !> Procedure to initialise mpi
     subroutine initialise_mpi(feedback)
         implicit none
@@ -217,7 +217,7 @@ subroutine mpi_synchronise(mpi_information)
         implicit none
         type(mpi_bundle), intent(in) :: mpi_information
 
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_BARRIER(mpi_information%communicator,mpierror)
 #endif 
 
diff --git a/src/polychord/nested_sampling.F90 b/src/polychord/nested_sampling.F90
index 0db480ae..b2e6600d 100644
--- a/src/polychord/nested_sampling.F90
+++ b/src/polychord/nested_sampling.F90
@@ -1,7 +1,7 @@
 module nested_sampling_module
     use utils_module, only: dp
 
-#ifdef MPI
+#ifdef USE_MPI
     use mpi_module, only: get_mpi_information,mpi_bundle,is_root,linear_mode,catch_babies,throw_babies,throw_seed,catch_seed,broadcast_integers,mpi_synchronise
 #else
     use mpi_module, only: get_mpi_information,mpi_bundle,is_root,linear_mode
@@ -23,7 +23,7 @@ function NestedSampling(loglikelihood,prior, dumper, settings, mpi_communicator)
         use cluster_module,    only: do_clustering
         use generate_module,   only: GenerateSeed,GenerateLivePoints,GenerateLivePointsFromSeed
         use maximise_module,   only: maximise
-#ifdef MPI
+#ifdef USE_MPI
         use utils_module, only: normal_fb,stdout_unit
 #else
         use utils_module, only: stdout_unit
@@ -114,7 +114,7 @@ end subroutine dumper
         type(mpi_bundle) :: mpi_information
 
 
-#ifdef MPI
+#ifdef USE_MPI
         ! MPI specific variables
         ! ----------------------
         integer                            :: i_worker       ! Worker iterator
@@ -142,7 +142,7 @@ end subroutine dumper
         ! MPI initialisation
         mpi_information = get_mpi_information(mpi_communicator)
 
-#ifdef MPI
+#ifdef USE_MPI
         allocate(worker_cluster(mpi_information%nprocs-1)) ! Allocate the worker arrays
         worker_cluster = 1                          ! initialise with 1
 
@@ -222,7 +222,7 @@ end subroutine dumper
             num_repeats = RTI%num_repeats
             call write_num_repeats(num_repeats,settings%feedback)
         end if
-#ifdef MPI
+#ifdef USE_MPI
         call broadcast_integers(num_repeats,mpi_information)
         allocate(nursary(settings%nTotal,sum(num_repeats), mpi_information%nprocs-1))
         allocate(worker_epochs(mpi_information%nprocs-1), nlikes(size(settings%grade_dims),mpi_information%nprocs-1))
@@ -262,7 +262,7 @@ end subroutine dumper
                     ! Generate a new set of points within the likelihood bound of the late point
                     baby_points = SliceSampling(loglikelihood,prior,settings,logL,seed_point,cholesky,nlike,num_repeats)
                     baby_points(settings%b0,:) = logL ! Note the moment it is born at
-#ifdef MPI
+#ifdef USE_MPI
                 else if(settings%synchronous) then
                     ! Parallel synchronous mode
                     ! -------------------------
@@ -313,7 +313,7 @@ end subroutine dumper
 
 
                 ! See if this point is suitable to be added to the arrays
-#ifdef MPI
+#ifdef USE_MPI
                 if( linear_mode(mpi_information) .or. administrator_epoch==worker_epoch ) then
 #endif
                     if(replace_point(settings,RTI,baby_points,cluster_id)) then
@@ -341,7 +341,7 @@ end subroutine dumper
                     end if
 
                     if(delete_cluster(settings,RTI)) then
-#ifdef MPI
+#ifdef USE_MPI
                         administrator_epoch = administrator_epoch+1
 #endif
                     end if! Delete any clusters as necessary
@@ -357,21 +357,21 @@ end subroutine dumper
                             ! If we want to cluster on sub dimensions, then do this first
                             if(allocated(settings%sub_clustering_dimensions)) then
                                 if( do_clustering(settings,RTI,settings%sub_clustering_dimensions) )  then
-#ifdef MPI
+#ifdef USE_MPI
                                     administrator_epoch = administrator_epoch+1
 #endif
                                 end if
                             end if
 
                             if( do_clustering(settings,RTI) )  then
-#ifdef MPI
+#ifdef USE_MPI
                                 administrator_epoch = administrator_epoch+1
 #endif
                             end if
                         end if
                         call calculate_covmats(settings,RTI)
                     end if
-#ifdef MPI
+#ifdef USE_MPI
                 end if
 #endif
 
@@ -421,7 +421,7 @@ end subroutine dumper
             ! C) Clean up
             !    ========
 
-#ifdef MPI
+#ifdef USE_MPI
             ! MPI cleanup
             ! -----------
             ! Kill off the final workers.
@@ -429,7 +429,7 @@ end subroutine dumper
             ! data from each node (and throw it away) and then send a kill signal back to it
             if (settings%synchronous) then
                 do worker_id=mpi_information%nprocs-1,1,-1
-                    call throw_seed(seed_point,cholesky,logL,mpi_information,worker_id,administrator_epoch,.false.) 
+                    call throw_seed(seed_point,cholesky,logL,mpi_information,worker_id,administrator_epoch,.false.)
                 end do
             else
                 do i_worker=mpi_information%nprocs-1,1,-1
@@ -441,7 +441,7 @@ end subroutine dumper
                     RTI%nlike = RTI%nlike + nlike
 
                     ! Send kill signal to worker worker_id (note that we no longer care about seed_point, so we'll just use the last one
-                    call throw_seed(seed_point,cholesky,logL,mpi_information,worker_id,administrator_epoch,.false.) 
+                    call throw_seed(seed_point,cholesky,logL,mpi_information,worker_id,administrator_epoch,.false.)
                 end do
             end if
 
@@ -504,7 +504,7 @@ end subroutine dumper
 #endif
         end if !(myrank==root / myrank/=root) 
 
-#ifdef MPI
+#ifdef USE_MPI
         call mpi_synchronise(mpi_information)
 #endif
 
diff --git a/src/polychord/random_utils.F90 b/src/polychord/random_utils.F90
index 1192606e..d27238eb 100644
--- a/src/polychord/random_utils.F90
+++ b/src/polychord/random_utils.F90
@@ -4,7 +4,7 @@
 module random_module
     use utils_module, only: dp
 
-#ifdef MPI
+#ifdef USE_MPI
     use mpi_module
 #endif
 
@@ -32,7 +32,7 @@ subroutine initialise_random(mpi_communicator,seed_input)
         integer, optional, intent(in) :: seed_input
 
         integer,allocatable,dimension(:) :: seed ! vector to be passed to random_seed
-#ifdef MPI
+#ifdef USE_MPI
         integer :: mpierror
 #endif
 
@@ -46,7 +46,7 @@ subroutine initialise_random(mpi_communicator,seed_input)
 
 
         ! Get the global ranking
-#ifdef MPI
+#ifdef USE_MPI
         call MPI_COMM_RANK(mpi_communicator, myrank, mpierror)
 #else
         myrank = 0
@@ -76,7 +76,7 @@ subroutine initialise_random(mpi_communicator,seed_input)
 
         end if
 
-#ifdef MPI
+#ifdef USE_MPI
         ! Broadcast the system time to all nodes
         call MPI_BCAST(t,1,MPI_INTEGER,0,mpi_communicator,mpierror)      
 
diff --git a/src/polychord/utils.F90 b/src/polychord/utils.F90
index 105e09a4..e5f406a3 100644
--- a/src/polychord/utils.F90
+++ b/src/polychord/utils.F90
@@ -1,7 +1,7 @@
 
 module utils_module
     implicit none
-#ifdef MPI
+#ifdef USE_MPI
     include 'mpif.h'
 #endif
     integer, parameter :: dp = kind(1.d0)
@@ -1050,12 +1050,12 @@ end function log_gauss
     !> This gets the wallclock timer from the mpi library
     function time() 
         implicit none
-#ifdef MPI
+#ifdef USE_MPI
         include 'mpif.h'
 #endif
         real(dp) :: time
 
-#ifdef MPI
+#ifdef USE_MPI
         time = MPI_Wtime()
 #else 
         call cpu_time(time)