diff --git a/.github/docker/Dockerfile.pecl-alpine b/.github/docker/Dockerfile.pecl-alpine
new file mode 100644
index 000000000..fd5889d6c
--- /dev/null
+++ b/.github/docker/Dockerfile.pecl-alpine
@@ -0,0 +1,15 @@
+FROM php:alpine
+
+RUN apk add --no-cache \
+    autoconf \
+    build-base \
+    openssl-dev
+
+COPY mongodb-*.tgz /tmp/mongodb.tgz
+
+# Install from the PECL package (fresh configure+build in a temp directory,
+# same as a real user install, but without zstd available)
+RUN pecl install --nodeps /tmp/mongodb.tgz < /dev/null
+
+# Verify the extension loads correctly
+RUN php -n -d extension=mongodb.so --ri mongodb
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 078bcdd3a..ee3687805 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -130,6 +130,11 @@ jobs:
       - name: "Install release archive to verify correctness"
         run: sudo pecl install ${{ env.PACKAGE_FILE }}
 
+      - name: "Install on Alpine Linux"
+        run: |
+          cp "${{ env.PACKAGE_FILE }}" .github/docker/
+          docker build .github/docker/ -f .github/docker/Dockerfile.pecl-alpine
+
   windows-test:
     name: "Windows Tests"
     runs-on: "${{ matrix.os }}"
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 89e1c2edb..155d3bad6 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -28,6 +28,23 @@ will report `phpinfo()` output for the extension:
 $ php --ri mongodb
 ```
 
+## Testing the PECL package on Alpine Linux
+
+Alpine Linux uses musl libc instead of glibc and does not include zstd by default. It is
+a popular base image for PHP Docker containers and represents a distinct build environment
+from RHEL/Debian. Testing PECL installation on Alpine catches issues that would not appear
+on glibc-based systems, such as missing POSIX extensions (e.g. `GLOB_BRACE`) or generated
+config headers that are incorrectly bundled in the package.
+
+First generate the PECL package, then test installation on Alpine:
+
+```
+make package.xml RELEASE_NOTES_FILE=/dev/null
+make package
+cp mongodb-*.tgz .github/docker/
+docker build .github/docker/ -f .github/docker/Dockerfile.pecl-alpine
+```
+
 ## Generating arginfo from stub files
 
 Arginfo structures are generated from stub files using the `gen_stub.php`
diff --git a/bin/prep-release.php b/bin/prep-release.php
index 7ca4b6950..494cbee83 100644
--- a/bin/prep-release.php
+++ b/bin/prep-release.php
@@ -1,4 +1,9 @@
 <?php
+if (!defined('GLOB_BRACE')) {
+    echo "Error: GLOB_BRACE is not available on this system\n";
+    exit(1);
+}
+
 function verify_stability($stability) {
     $stabilities = array(
         "snapshot",
@@ -74,8 +79,6 @@ function get_files() {
         "src/libmongocrypt/kms-message/src/kms_message/*.{c,h}",
       ),
       'test' => array(
-        "Vagrantfile",
-
         "scripts/*/*.{sh}",
         "scripts/*.{json,php,py,sh}",
         "tests/utils/*.{inc,json.gz,php}",
@@ -92,7 +95,7 @@ function get_files() {
     $files = array();
     foreach($dirs as $role => $patterns) {
         foreach ($patterns as $pattern) {
-            foreach (glob($pattern, GLOB_BRACE) as $file) {
+            foreach (glob($pattern, GLOB_BRACE) ?: [] as $file) {
                 $files[$file] = $role;
             }
         }
@@ -215,4 +218,3 @@ function usage() {
 
 file_put_contents(__DIR__ . "/../package.xml", $contents);
 echo "Wrote package.xml\n";
-