diff --git a/.github/workflows/pr-check.yml b/.github/workflows/pr-check.yml
index cfc15595..a6cb1c9a 100644
--- a/.github/workflows/pr-check.yml
+++ b/.github/workflows/pr-check.yml
@@ -63,6 +63,47 @@ jobs:
         with:
           files: coverage.json
 
+  mac-unittest:
+    name: python${{ matrix.python-version }}
+    runs-on: macos-latest
+
+    strategy:
+      matrix:
+        python-version:
+          - '3.11'
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install test dependencies
+        run: |
+          brew install modules alisw/system-deps/o2-full-deps
+          python -m pip install --upgrade tox tox-gh-actions coverage
+
+      - name: Run tests
+        run: tox
+
+      - name: Convert coverage information
+        if: ${{ always() && github.event.repository.owner.login == 'alisw' }}
+        run: |
+          coverage combine .tox/coverage.*
+          # Codecov only understands XML, JSON and LCOV files.
+          # Apparently, patching os.readlink in unit tests interferes with
+          # finding some source files, but our source shouldn't be affected, so
+          # ignore these errors.
+          coverage json --ignore-errors -o coverage.json
+
+      - name: Upload coverage information
+        if: ${{ always() && github.event.repository.owner.login == 'alisw' }}
+        uses: codecov/codecov-action@v3
+        with:
+          files: coverage.json
+
   lint:
     name: lint
     runs-on: ubuntu-latest
diff --git a/alibuild_helpers/utilities.py b/alibuild_helpers/utilities.py
index c7361355..b27643a4 100644
--- a/alibuild_helpers/utilities.py
+++ b/alibuild_helpers/utilities.py
@@ -134,10 +134,13 @@ def format(s, **kwds):
 def doDetectArch(hasOsRelease, osReleaseLines, platformTuple, platformSystem, platformProcessor):
   if platformSystem == "Darwin":
     import platform
-    if platform.machine() == "x86_64":
-      return "osx_x86-64"
-    else:
-      return "osx_arm64"
+    processor = platformProcessor
+    if not processor:
+      if platform.machine() == "x86_64":
+        processor = "x86-64"
+      else:
+        processor = "arm64"
+    return "osx_%s" % processor.replace("_", "-")
   distribution, version, flavour = platformTuple
   distribution = distribution.lower()
   # If platform.dist does not return something sensible,
diff --git a/tests/test_utilities.py b/tests/test_utilities.py
index b8254053..be654921 100644
--- a/tests/test_utilities.py
+++ b/tests/test_utilities.py
@@ -115,6 +115,7 @@
 
 architecturePayloads = [
   ['osx_x86-64', False, [], ('','',''), 'Darwin', 'x86-64'],
+  ['osx_arm64', False, [], ('','',''), 'Darwin', 'arm64'],
   ['slc5_x86-64', False, [], ('redhat', '5.XX', 'Boron'), 'Linux', 'x86-64'],
   ['slc6_x86-64', False, [], ('centos', '6.X', 'Carbon'), 'Linux', 'x86-64'],
   ['slc7_x86-64', False, [], ('centos', '7.X', 'Ptor'), 'Linux', 'x86-64'],
diff --git a/tox.ini b/tox.ini
index 06a35a42..440f8ed6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -57,6 +57,8 @@ setenv =
     # Keep coverage info for later upload, if needed. Files in {envtmpdir} are
     # deleted after each run.
     COVERAGE_FILE = {toxworkdir}/coverage.{envname}
+    ARCHITECTURE = slc7_x86-64
+    darwin: ARCHITECTURE = osx_x86-64
 
 changedir = {envtmpdir}
 commands =
@@ -78,10 +80,10 @@ commands =
 
     git clone -b O2-v1.3.0 --depth 1 https://github.com/alisw/alidist
 
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a slc7_x86-64 -z test-init init zlib
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a {env:ARCHITECTURE} -z test-init init zlib
     # This command is expected to fail, but run it for the coverage anyway.
     # A leading "-" means tox ignores the exit code.
-    - coverage run --source={toxinidir} -a {toxinidir}/aliBuild build non-existing -a slc7_x86-64 --no-system --disable GCC-Toolchain
+    - coverage run --source={toxinidir} -a {toxinidir}/aliBuild build non-existing -a {env:ARCHITECTURE} --no-system --disable GCC-Toolchain
 
     # TODO: do we need these? This seems to be at least partially covered by
     # unit tests in tests/tests_parseRecipe.py.
@@ -93,19 +95,19 @@ commands =
     sh -c 'coverage run --source={toxinidir} -a {toxinidir}/aliBuild -c {toxinidir}/tests/testdist build broken6 --force-unknown-architecture --no-system --disable GCC-Toolchain 2>&1 | tee /dev/stderr | grep "while scanning a quoted scalar"'
     sh -c 'coverage run --source={toxinidir} -a {toxinidir}/aliBuild -c {toxinidir}/tests/testdist build broken7 --force-unknown-architecture --no-system --disable GCC-Toolchain 2>&1 | tee /dev/stderr | grep "Malformed entry prefer_system"'
 
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild build zlib -a slc7_x86-64 --no-system --disable GCC-Toolchain
-    alienv -a slc7_x86-64 q
-    alienv -a slc7_x86-64 setenv zlib/latest -c bash -c '[[ $LD_LIBRARY_PATH == */zlib/* ]]'
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a slc7_x86-64 doctor AliPhysics
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a slc7_x86-64 build zlib --dry-run
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild --aggressive-cleanup --docker -a slc7_x86-64 --always-prefer-system -d build zlib
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild build zlib -a {env:ARCHITECTURE} --no-system --disable GCC-Toolchain
+    alienv -a {env:ARCHITECTURE} q
+    alienv -a {env:ARCHITECTURE} setenv zlib/latest -c bash -c '[[ $LD_LIBRARY_PATH == */zlib/* ]]'
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a {env:ARCHITECTURE} doctor AliPhysics
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a {env:ARCHITECTURE} build zlib --dry-run
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild --aggressive-cleanup --docker -a {env:ARCHITECTURE} --always-prefer-system -d build zlib
     # Test for devel packages
     coverage run --source={toxinidir} -a {toxinidir}/aliBuild init zlib
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild --aggressive-cleanup --docker -a slc7_x86-64 --always-prefer-system -d build zlib
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild --aggressive-cleanup --docker -a {env:ARCHITECTURE} --always-prefer-system -d build zlib
     # Test that we complain if we have a devel package with an untracked file
     coverage run --source={toxinidir} -a {toxinidir}/aliBuild init zlib
     touch zlib/foo
-    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a slc7_x86-64 --no-system --disable GCC-Toolchain build zlib
+    coverage run --source={toxinidir} -a {toxinidir}/aliBuild -a {env:ARCHITECTURE} --no-system --disable GCC-Toolchain build zlib
 
 [coverage:run]
 branch = True