diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f05844d..bb87ee7 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,21 +5,38 @@ on:
 jobs:
   tests:
     runs-on: ubuntu-latest
+    continue-on-error: ${{ matrix.experimental }}
 
     strategy:
       matrix:
-        php: [8.1, 8.2, 8.3, 8.4]
+        php: [8.1, 8.2, 8.3, 8.4, 8.5]
+        experimental: [false]
+        include:
+          - php: 8.6
+            experimental: true
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Setup PHP
+      if: ${{ matrix.php != '8.5' }}
       uses: shivammathur/setup-php@v2
       with:
         php-version: ${{ matrix.php }}
         coverage: none
 
+    - name: Setup PHP with register_arg_argv
+      uses: shivammathur/setup-php@v2
+      if: ${{ matrix.php == '8.5' }}
+      with:
+        php-version: ${{ matrix.php }}
+        coverage: none
+        # this ini directive seems to be off by default in PHP 8.5
+        # see https://github.com/php/php-src/issues/20279
+        # enable it because codeception relies on it.
+        ini-values: register_argc_argv=1
+
     - name: Validate composer.json and composer.lock
       run: composer validate
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index fb8341c..47f35ad 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,17 +9,21 @@ jobs:
 
     strategy:
       matrix:
-        php: [ 8.1, 8.2, 8.3, 8.4 ]
+        php: [ 8.1, 8.2, 8.3, 8.4, 8.5 ]
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
           coverage: none
+          # this ini directive seems to be off by default in PHP 8.5
+          # see https://github.com/php/php-src/issues/20279
+          # enable it because codeception relies on it.
+          ini-values: register_argc_argv=1
 
       - name: Validate composer.json and composer.lock
         run: composer validate
@@ -46,7 +50,7 @@ jobs:
       - tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: false