diff --git a/.github/workflows/ci-php.yml b/.github/workflows/ci-php.yml
index 37c9dc7a8..882d63055 100644
--- a/.github/workflows/ci-php.yml
+++ b/.github/workflows/ci-php.yml
@@ -19,12 +19,18 @@ jobs:
   test:
     name: "PHPUnit: MW ${{ matrix.mw }}, PHP ${{ matrix.php }}"
 
+    continue-on-error: ${{ matrix.experimental }}
+
     strategy:
       fail-fast: false
       matrix:
         include:
           - mw: 'REL1_43'
             php: '8.3'
+            experimental: false
+          - mw: 'master'
+            php: '8.5'
+            experimental: true
 
     runs-on: ubuntu-latest
 
diff --git a/.github/workflows/installMediaWiki.sh b/.github/workflows/installMediaWiki.sh
index 2ca5b881e..d957a0bab 100644
--- a/.github/workflows/installMediaWiki.sh
+++ b/.github/workflows/installMediaWiki.sh
@@ -13,6 +13,16 @@ cd mediawiki
 composer install
 php maintenance/install.php --dbtype sqlite --dbuser root --dbname mw --dbpath $(pwd) --pass AdminPassword WikiName AdminUser
 
+# MediaWiki 1.46 replaced `phpunit.xml.dist` with `phpunit.xml.template`, which
+# is turned into a runnable `phpunit.xml` by `generatePHPUnitConfig.php`. The
+# extension's `composer phpunit` script invokes `-c phpunit.xml.dist`, so on
+# branches that only ship a template, generate the config and expose it under the
+# name the script expects. Generated here (after `composer install` provides the
+# autoloader, before the extension load lines are appended to LocalSettings.php).
+if [ ! -f phpunit.xml.dist ] && [ -f phpunit.xml.template ]; then
+    php tests/phpunit/generatePHPUnitConfig.php
+    cp phpunit.xml phpunit.xml.dist
+fi
 
 cat <<'EOT' >> LocalSettings.php
 error_reporting(E_ALL| E_STRICT);