diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 447f0796c..26fe992bc 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -116,14 +116,24 @@ jobs:
           platforms: all
 
       - name: Build and test wheels
-        uses: pypa/cibuildwheel@v2.16.5
+        uses: pypa/cibuildwheel@v4.3.3
         env:
           # configure cibuildwheel to build native archs ('auto'), and some
           # emulated ones
           CIBW_ARCHS_LINUX: "auto aarch64"
           CIBW_ARCHS_MACOS: "universal2"
-          CIBW_BUILD: "cp39-*"
+          # The wheel is abi3, so it is built once on cp39. cibuildwheel skips
+          # the build for cp315 because the abi3 wheel already covers it, and
+          # only reruns the tests there, so the oldest and newest supported
+          # interpreters both load the extension.
+          CIBW_BUILD: "cp39-* cp315-*"
           CIBW_SKIP: "pp* *-musllinux* *-manylinux_i686"
+          # cibuildwheel v3+ builds on manylinux_2_28 (glibc 2.28) by default.
+          # Pin manylinux2014 (glibc 2.17) so CentOS/RHEL 7, Amazon Linux 2 and
+          # Ubuntu 18.04 still get the C extension instead of falling back to
+          # the pure-Python wheel without any warning.
+          CIBW_MANYLINUX_X86_64_IMAGE: manylinux2014
+          CIBW_MANYLINUX_AARCH64_IMAGE: manylinux2014
           CIBW_TEST_COMMAND: "pytest -v --pyargs singlestoredb.tests.test_basics"
           # xdist because pyproject.toml's addopts sets -n/--dist, and PYTHONPATH
           # points --pyargs at the workspace, so that pyproject is the inifile
diff --git a/accel.c b/accel.c
index 075276287..dd53bd619 100644
--- a/accel.c
+++ b/accel.c
@@ -371,7 +371,7 @@ static PyObject *create_numpy_array(PyObject *py_memview, char *data_format, int
 
 // Returns a newly allocated UTF-8 copy of `unicode`; the caller owns it
 // and must free() it.
-char *_PyUnicode_AsUTF8(PyObject *unicode) {
+static char *_PyUnicode_AsUTF8(PyObject *unicode) {
     PyObject *bytes = PyUnicode_AsEncodedString(unicode, "utf-8", "strict");
     if (!bytes) return NULL;