diff --git a/.github/workflows/build-bitarray-hardbyte.yml b/.github/workflows/build-bitarray-hardbyte.yml
new file mode 100644
index 000000000..97241ce49
--- /dev/null
+++ b/.github/workflows/build-bitarray-hardbyte.yml
@@ -0,0 +1,112 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# bitarray-hardbyte is a one-off PyPI redistribution of ilanschnell/bitarray
+# under a different project name (see the docs entry / PR description); this
+# workflow is based on the `build_wheels` job of
+# https://github.com/ilanschnell/bitarray/blob/50b62ede70b9ef5f553e1463bb912d2bc45a174d/.github/workflows/build_wheels.yml
+name: Build bitarray-hardbyte wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'bitarray-hardbyte version to build (e.g. 2.3.8)'
+        required: true
+        default: '2.3.8'
+  pull_request:
+    paths:
+      - '.github/workflows/build-bitarray-hardbyte.yml'
+      - 'patches/bitarray-hardbyte/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ inputs.version || '2.3.8' }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  # `inputs.version` is empty on pull_request events; default to 2.3.8 there.
+  BITARRAY_HARDBYTE_VERSION: ${{ inputs.version || '2.3.8' }}
+  # bitarray-hardbyte 2.3.8 has no matching git tag in ilanschnell/bitarray
+  # (gotcha 103): this is "next release 2.3.8" (BITARRAY_VERSION bumped, never
+  # tagged upstream), advanced to the last commit before "next release 2.4.0"
+  # finalized. Every file is byte-identical to the PyPI sdist except setup.py's
+  # `name`, which patches/bitarray-hardbyte/2.3.8 restores. Update it alongside
+  # BITARRAY_HARDBYTE_VERSION.
+  BITARRAY_HARDBYTE_REF: 50b62ede70b9ef5f553e1463bb912d2bc45a174d
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+
+  build_wheels:
+    needs: [setup]
+    name: Build bitarray-hardbyte ${{ inputs.version || '2.3.8' }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        python:
+          - "cp312"
+          - "cp313"
+          - "cp314"
+          - "cp314t"
+
+    steps:
+      - name: Checkout bitarray-hardbyte ${{ env.BITARRAY_HARDBYTE_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: ilanschnell/bitarray
+          ref: ${{ env.BITARRAY_HARDBYTE_REF }}
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      - name: Patch bitarray-hardbyte source
+        run: git apply python-wheels/patches/bitarray-hardbyte/${{ env.BITARRAY_HARDBYTE_VERSION }}/*.patch
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        with:
+          output-dir: wheelhouse/
+          only: ${{ matrix.python }}-manylinux_riscv64
+        env:
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          CIBW_TEST_COMMAND: python -c "import bitarray; assert bitarray.test().wasSuccessful()"
+
+      - name: Check the C extensions and LICENSE made it into the wheel
+        run: |
+          python3 - wheelhouse/*.whl <<'EOF'
+          import sys, zipfile
+          for whl in sys.argv[1:]:
+              names = zipfile.ZipFile(whl).namelist()
+              for mod in ("_bitarray", "_util"):
+                  assert any(mod in n and n.endswith(".so") for n in names), (whl, mod)
+              assert any(n.endswith(".dist-info/licenses/LICENSE")
+                         or n.endswith(".dist-info/LICENSE") for n in names), names
+              print(whl, "ok")
+          EOF
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: bitarray-hardbyte-${{ env.BITARRAY_HARDBYTE_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish bitarray-hardbyte ${{ inputs.version || '2.3.8' }}
+    needs: [setup, build_wheels]
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    with:
+      artifact-pattern: bitarray-hardbyte-${{ inputs.version || '2.3.8' }}-*-manylinux_riscv64
diff --git a/patches/bitarray-hardbyte/2.3.8/0001-setup-rename-distribution-to-bitarray-hardbyte.patch b/patches/bitarray-hardbyte/2.3.8/0001-setup-rename-distribution-to-bitarray-hardbyte.patch
new file mode 100644
index 000000000..6350f5b12
--- /dev/null
+++ b/patches/bitarray-hardbyte/2.3.8/0001-setup-rename-distribution-to-bitarray-hardbyte.patch
@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Mon, 7 Sep 2026 13:32:21 +0000
+Subject: [PATCH] setup: rename distribution to bitarray-hardbyte
+
+Upstream-Status: Inappropriate [downstream redistribution naming, irrelevant to ilanschnell/bitarray]
+
+The PyPI project we are building wheels for is `bitarray-hardbyte`, a
+one-off redistribution of ilanschnell/bitarray published under a
+different project name (see the port's docs entry / PR description for
+how BITARRAY_HARDBYTE_REF was chosen: it is the commit where
+BITARRAY_VERSION was "2.3.8" and the cibuildwheel workflow that hardbyte
+contributed upstream in PR ilanschnell/bitarray#170 had just landed).
+That release's actual sdist on PyPI carries this same one-line rename in
+setup.py -- verified by diffing files.pythonhosted.org's
+bitarray-hardbyte-2.3.8.tar.gz against this commit, which is otherwise
+byte-identical. Reapply it so our wheel's distribution name matches the
+package we publish.
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ setup.py | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/setup.py b/setup.py
+index a477971..040e183 100644
+--- a/setup.py
++++ b/setup.py
+@@ -18,7 +18,7 @@ kwds['version'] = pat.search(data).group(1)
+
+
+ setup(
+-    name = "bitarray",
++    name = "bitarray-hardbyte",
+     author = "Ilan Schnell",
+     author_email = "ilanschnell@gmail.com",
+     url = "https://github.com/ilanschnell/bitarray",
+--
+2.50.1
diff --git a/patches/bitarray-hardbyte/2.3.8/0002-test_bitarray-replace-removed-unittest.makeSuite.patch b/patches/bitarray-hardbyte/2.3.8/0002-test_bitarray-replace-removed-unittest.makeSuite.patch
new file mode 100644
index 000000000..66ef2f70b
--- /dev/null
+++ b/patches/bitarray-hardbyte/2.3.8/0002-test_bitarray-replace-removed-unittest.makeSuite.patch
@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Mon, 7 Sep 2026 14:00:00 +0000
+Subject: [PATCH] test_bitarray: replace removed unittest.makeSuite()
+
+Upstream-Status: Backport [https://github.com/ilanschnell/bitarray/commit/d345e9a3b5cf6a8f876567b36551e48767a89a0e]
+
+unittest.makeSuite() was deprecated in Python 3.11 and removed in 3.13
+(bpo-45162 / gh-92220). bitarray-hardbyte is pinned to a 2022 commit
+whose test_bitarray.py still calls it, so `bitarray.test()` raises
+AttributeError under cp313/cp314/cp314t: "module 'unittest' has no
+attribute 'makeSuite'". This reproduces on any architecture running
+those interpreters, not just riscv64.
+
+Upstream fixed this the same way in d345e9a3 ("avoid deprecated
+unittest.makeSuite", 2023-09-16), once bitarray/test_bitarray.py had
+moved past line 4431; this backports that one-line change onto our
+pinned commit rather than dropping test coverage from the workflow.
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ bitarray/test_bitarray.py | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/bitarray/test_bitarray.py b/bitarray/test_bitarray.py
+index b126b2e..014a564 100644
+--- a/bitarray/test_bitarray.py
++++ b/bitarray/test_bitarray.py
+@@ -4428,7 +4428,7 @@ def run(verbosity=1, repeat=1):
+     suite = unittest.TestSuite()
+     for cls in tests:
+         for _ in range(repeat):
+-            suite.addTest(unittest.makeSuite(cls))
++            suite.addTest(unittest.TestLoader().loadTestsFromTestCase(cls))
+
+     runner = unittest.TextTestRunner(verbosity=verbosity)
+     return runner.run(suite)
+--
+2.50.1