diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 146a73f..6867b7d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,158 +1,44 @@
 name: Tests
-
-on: [pull_request, push]
-
+on: [push, pull_request]
 jobs:
-  tests:
-    env:
-      NPROC: 2
+  test:
     strategy:
-      fail-fast: false
       matrix:
-        cache_nonce: [ 1 ]
-        nim_version: [ 1.6.20 ] # add stable for testing 2.0+
         platform:
           - {
             icon: 🐧,
             label: Linux,
             os: ubuntu,
-            runner: ubuntu-latest,
-            shell: bash --noprofile --norc -eo pipefail
+            runner: ubuntu-latest
           }
           - {
             icon: 🍎,
             label: macOS,
             os: macos,
-            runner: macos-13, # x86
-            shell: bash --noprofile --norc -eo pipefail
+            runner: macos-13 # x86
           }
           - {
             icon: 🏁,
             label: Windows,
             os: windows,
-            runner: windows-latest,
-            shell: msys2
+            runner: windows-latest
           }
-    name: ${{ matrix.platform.icon }} ${{ matrix.platform.label }} - Nim v${{ matrix.nim_version }}
-    runs-on: ${{ matrix.platform.runner }}
+        nim: [1.6.18]
+    name: ${{ matrix.platform.icon }} ${{ matrix.platform.label }} - Nim v${{ matrix.nim }}
+    runs-on: ${{ matrix.platform.os }}-latest
     defaults:
       run:
-        shell: ${{ matrix.platform.shell }} {0}
-
+        shell: bash
     steps:
-      # - name: Install tools and libraries via APT (Linux)
-      #   if: matrix.platform.os == 'ubuntu'
-      #   run: |
-      #     sudo apt update
-      #     sudo apt install -y \
-      #       ...
-
-      - name: Install tools and libraries via Homebrew (macOS)
-        if: matrix.platform.os == 'macos'
-        run: |
-          brew update
-          brew install \
-            findutils \
-            libomp \
-            llvm@14
-
-      - name: Install tools and libraries via MSYS2 (Windows)
-        if: matrix.platform.os == 'windows'
-        uses: msys2/setup-msys2@v2
-        with:
-          msystem: UCRT64
-          install: >
-            base-devel
-            git
-            mingw-w64-ucrt-x86_64-cmake
-            mingw-w64-ucrt-x86_64-toolchain
-
-      - name: Checkout sources from GitHub
-        uses: actions/checkout@v2
-        with:
-          submodules: true
-
-      - name: Calculate cache member paths
-        id: calc-paths
-        run: |
-          if [[ ${{ matrix.platform.os }} = windows ]]; then
-            echo "::set-output name=bash_env::$(cygpath -m "${HOME}")/.bash_env"
-            echo "::set-output name=choosenim::$(cygpath -m "${USERPROFILE}")/.choosenim"
-            echo "::set-output name=nimble::$(cygpath -m "${HOME}")/.nimble"
-          else
-            echo "::set-output name=bash_env::${HOME}/.bash_env"
-            echo "::set-output name=choosenim::${HOME}/.choosenim"
-            echo "::set-output name=nimble::${HOME}/.nimble"
-          fi
-
-      - name: Restore choosenim and Nim tooling from cache
-        id: choosenim-nim-tooling-cache
-        uses: actions/cache@v2
-        with:
-          path: |
-            ${{ steps.calc-paths.outputs.bash_env }}
-            ${{ steps.calc-paths.outputs.choosenim }}
-            ${{ steps.calc-paths.outputs.nimble }}/bin
-          key: ${{ matrix.platform.os }}-nim_version:${{ matrix.nim_version }}-cache_nonce:${{ matrix.cache_nonce }}
-
-      - name: Install choosenim and Nim tooling
-        if: steps.choosenim-nim-tooling-cache.outputs.cache-hit != 'true'
-        run: |
-          mkdir -p "${HOME}/Downloads"
-          cd "${HOME}/Downloads"
-          curl https://nim-lang.org/choosenim/init.sh -sSf -O
-          chmod +x init.sh
-          if [[ ${{ matrix.platform.os }} = windows ]]; then
-            mkdir -p "$(cygpath "${USERPROFILE}")/.nimble/bin"
-          fi
-          CHOOSENIM_CHOOSE_VERSION=${{ matrix.nim_version }} ./init.sh -y
-          if [[ ${{ matrix.platform.os }} = windows ]]; then
-            mv "$(cygpath "${USERPROFILE}")/.nimble" "${HOME}/"
-            # intention is to rely only on libs provided by the OS and MSYS2 env
-            rm -rf "${HOME}/.nimble/bin/"*.dll
-            rm -rf "${HOME}/.nimble/bin/"*.pem
-          fi
-          echo 'export NIMBLE_DIR="${HOME}/.nimble"' >> "${HOME}/.bash_env"
-          echo 'export PATH="${NIMBLE_DIR}/bin:${PATH}"' >> "${HOME}/.bash_env"
-
-      - name: Install project dependencies
-        run: |
-          source "${HOME}/.bash_env"
-          cd "${NIMBLE_DIR}/bin"
-          # delete broken symlinks, which can arise because e.g. the cache
-          # restored a symlink that points to an executable within
-          # ../pkgs/foo-1.2.3/ but the project's .nimble file has been updated
-          # to install foo-#head; in the case of a broken symlink, nimble's
-          # auto-overwrite fails
-          if [[ ${{ matrix.platform.os }} = macos ]]; then
-            gfind . -xtype l -delete
-          else
-            find . -xtype l -delete
-          fi
-          cd -
-          nimble --accept install
-
-      - name: Build and run tests
-        run: |
-          source "${HOME}/.bash_env"
-          if [[ ${{ matrix.platform.os }} = windows ]]; then
-            touch tests/testleopard.exe
-          else
-            touch tests/testleopard
-          fi
-          if [[ ${{ matrix.platform.os }} = macos ]]; then
-            export PATH="$(brew --prefix llvm@14)/bin:${PATH}"
-            export LDFLAGS="-L$(brew --prefix libomp)/lib -L$(brew --prefix llvm@14)/lib -Wl,-rpath,$(brew --prefix llvm@14)/lib"
-            compiler_extra_options="-d:LeopardCmakeFlags='-DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=$(brew --prefix llvm@14)/bin/clang -DCMAKE_CXX_COMPILER=$(brew --prefix llvm@14)/bin/clang++' -d:LeopardExtraCompilerlags='-fopenmp' -d:LeopardExtraLinkerFlags='-fopenmp -L$(brew --prefix libomp)/lib'"
-          fi
-          eval nimble --verbose test -d:release --mm:refc ${compiler_extra_options}
-          eval nimble --verbose test -d:release --mm:orc ${compiler_extra_options}
-          if [[ ${{ matrix.platform.os }} = macos ]]; then
-            echo
-            echo otool -L tests/testleopard
-            otool -L tests/testleopard
-          else
-            echo
-            echo ldd tests/testleopard
-            ldd tests/testleopard
-          fi
+    - uses: actions/checkout@v4
+      with:
+        submodules: true
+    - uses: iffy/install-nim@v4
+      with:
+        version: ${{ matrix.nim }}
+    - name: Install
+      run: nimble install -y
+    - name: Build and run tests
+      run: |
+        eval nimble --verbose test -d:release --mm:refc
+        eval nimble --verbose test -d:release --mm:orc
diff --git a/leopard/leopard.nim b/leopard/leopard.nim
index dd749b9..615f7ad 100644
--- a/leopard/leopard.nim
+++ b/leopard/leopard.nim
@@ -77,7 +77,7 @@ func encode*(
       self.buffers.cuint,
       self.parity.cuint,
       self.workBufferCount.cuint,
-      cast[ptr pointer](addr self.dataBufferPtr[0]),
+      cast[LeoDataPtr](addr self.dataBufferPtr[0]),
       cast[ptr pointer](addr self.workBufferPtr[0]))
 
   if ord(res) != ord(LeopardSuccess):
@@ -148,8 +148,8 @@ func decode*(
       self.buffers.cuint,
       self.parity.cuint,
       self.decodeBufferCount.cuint,
-      cast[ptr pointer](addr dataPtr[0]),
-      cast[ptr pointer](addr parityPtr[0]),
+      cast[LeoDataPtr](addr dataPtr[0]),
+      cast[LeoDataPtr](addr parityPtr[0]),
       cast[ptr pointer](addr self.decodeBufferPtr[0]))
 
   if ord(res) != ord(LeopardSuccess):
diff --git a/leopard/wrapper.nim b/leopard/wrapper.nim
index da29704..90d8b5a 100644
--- a/leopard/wrapper.nim
+++ b/leopard/wrapper.nim
@@ -67,6 +67,9 @@ import std/compilesettings
 import std/os
 import std/strutils
 
+type
+  LeoDataPtr* {.importc: "const void* const*", bycopy.} = pointer
+
 const
   LeopardCmakeFlags {.strdefine.} =
     when defined(macosx):
@@ -225,7 +228,7 @@ proc leoEncode*(
   originalCount: cuint;
   recoveryCount: cuint;
   workCount: cuint;
-  originalData: ptr pointer;
+  originalData: LeoDataPtr;
   workData: ptr pointer): LeopardResult {.leo, importc: "leo_encode".}
   ##  Number of bytes in each data buffer
   ##  Number of original_data[] buffer pointers
@@ -277,8 +280,8 @@ proc leoDecode*(
   originalCount: cuint;
   recoveryCount: cuint;
   workCount: cuint;
-  originalData: ptr pointer;
-  recoveryData: ptr pointer;
+  originalData: LeoDataPtr;
+  recoveryData: LeoDataPtr;
   workData: ptr pointer): LeopardResult {.leo, importc: "leo_decode".}
   ##  Number of bytes in each data buffer
   ##  Number of original_data[] buffer pointers