diff --git a/.appveyor/install.ps1 b/.appveyor/install.ps1
index fbcd032..6ee46d7 100644
--- a/.appveyor/install.ps1
+++ b/.appveyor/install.ps1
@@ -1,64 +1,61 @@
 $ErrorActionPreference = "Stop"
 
-if (-not (Test-Path 'C:\build-cache')) {
-    [void](New-Item 'C:\build-cache' -ItemType 'directory')
+if (-not (Test-Path 'c:\build-cache')) {
+    [void](New-Item 'c:\build-cache' -ItemType 'directory')
 }
 
 $bname = "php-sdk-$env:BIN_SDK_VER.zip"
-if (-not (Test-Path "C:\build-cache\$bname")) {
-    Invoke-WebRequest "https://github.com/Microsoft/php-sdk-binary-tools/archive/$bname" -OutFile "C:\build-cache\$bname"
+Write-Host $bname
+if (-not (Test-Path c:\build-cache\$bname)) {
+    Invoke-WebRequest "https://github.com/microsoft/php-sdk-binary-tools/archive/$bname" -OutFile "c:\build-cache\$bname"
 }
 $dname0 = "php-sdk-binary-tools-php-sdk-$env:BIN_SDK_VER"
 $dname1 = "php-sdk-$env:BIN_SDK_VER"
-if (-not (Test-Path "C:\build-cache\$dname1")) {
-    Expand-Archive "C:\build-cache\$bname" 'C:\build-cache'
-    Move-Item "C:\build-cache\$dname0" "C:\build-cache\$dname1"
+if (-not (Test-Path 'c:\build-cache\$dname1')) {
+    Expand-Archive "c:\build-cache\$bname" "c:\build-cache"
+    Move-Item "c:\build-cache\$dname0" "c:\build-cache\$dname1"
 }
 
-$gareleases = Invoke-WebRequest "https://windows.php.net/downloads/releases/releases.json" | ConvertFrom-Json
-$qareleases = Invoke-WebRequest "https://windows.php.net/downloads/qa/releases.json" | ConvertFrom-Json
-$garev = [regex]::split($gareleases.$env:PHP_VER.version, '[^\d]')[2]
-$qarev = [regex]::split($qareleases.$env:PHP_VER.version, '[^\d]')[2]
-if ($qarev -gt $garev) {
-    $phpversion = $qareleases.$env:PHP_VER.version
-    $phprelease = 'QA'
+$releases = @{
+    '7.0' = '7.0.33';
+    '7.1' = '7.1.33';
+    '7.2' = '7.2.34';
+    '7.3' = '7.3.33';
+}
+if ($releases.ContainsKey($env:PHP_VER)) {
+    $phpversion = $releases.$env:PHP_VER;
+    $base_url = 'http://windows.php.net/downloads/releases/archives';
 } else {
-    $phpversion = $gareleases.$env:PHP_VER.version
-    $phprelease = 'GA'
+    $releases = Invoke-WebRequest https://windows.php.net/downloads/releases/releases.json | ConvertFrom-Json
+    $phpversion = $releases.$env:PHP_VER.version
+    $base_url = 'http://windows.php.net/downloads/releases';
 }
 
 $ts_part = ''
 if ($env:TS -eq '0') {
     $ts_part += '-nts'
 }
+
 $bname = "php-devel-pack-$phpversion$ts_part-Win32-$env:VC-$env:ARCH.zip"
-if (-not (Test-Path "C:\build-cache\$bname")) {
-    if ($phprelease -eq "GA") {
-        Invoke-WebRequest "https://windows.php.net/downloads/releases/$bname" -OutFile "C:\build-cache\$bname"
-    } else {
-        Invoke-WebRequest "https://windows.php.net/downloads/qa/$bname" -OutFile "C:\build-cache\$bname"
-    }
+if (-not (Test-Path "c:\build-cache\$bname")) {
+    Invoke-WebRequest "$base_url/$bname" -OutFile "c:\build-cache\$bname"
 }
 $dname0 = "php-$phpversion-devel-$env:VC-$env:ARCH"
 $dname1 = "php-$phpversion$ts_part-devel-$env:VC-$env:ARCH"
-if (-not (Test-Path "C:\build-cache\$dname1")) {
-    Expand-Archive "C:\build-cache\$bname" 'C:\build-cache'
+if (-not (Test-Path "c:\build-cache\$dname1")) {
+    Expand-Archive "c:\build-cache\$bname" "c:\build-cache"
     if ($dname0 -ne $dname1) {
-        Move-Item "C:\build-cache\$dname0" "C:\build-cache\$dname1"
+        Move-Item "c:\build-cache\$dname0" "c:\build-cache\$dname1"
     }
 }
-$env:PATH = "C:\build-cache\$dname1;$env:PATH"
+$env:PATH = "c:\build-cache\$dname1;$env:PATH"
 
 $bname = "php-$phpversion$ts_part-Win32-$env:VC-$env:ARCH.zip"
-if (-not (Test-Path "C:\build-cache\$bname")) {
-    if ($phprelease -eq "GA") {
-        Invoke-WebRequest "https://windows.php.net/downloads/releases/$bname" -OutFile "C:\build-cache\$bname"
-    } else {
-        Invoke-WebRequest "https://windows.php.net/downloads/qa/$bname" -OutFile "C:\build-cache\$bname"
-    }
+if (-not (Test-Path "c:\build-cache\$bname")) {
+    Invoke-WebRequest "$base_url/$bname" -OutFile "c:\build-cache\$bname"
 }
 $dname = "php-$phpversion$ts_part-$env:VC-$env:ARCH"
-if (-not (Test-Path "C:\build-cache\$dname")) {
-    Expand-Archive "C:\build-cache\$bname" "C:\build-cache\$dname"
+if (-not (Test-Path "c:\build-cache\$dname")) {
+    Expand-Archive "c:\build-cache\$bname" "c:\build-cache\$dname"
 }
 $env:PATH = "c:\build-cache\$dname;$env:PATH"
diff --git a/.github/workflows/common.yml b/.github/workflows/common.yml
new file mode 100644
index 0000000..b446743
--- /dev/null
+++ b/.github/workflows/common.yml
@@ -0,0 +1,60 @@
+name: Run tests
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  tests:
+    name: Execute tests on ${{ matrix.operating-system }} with PHP ${{ matrix.php-versions }}
+    runs-on: ${{ matrix.operating-system }}
+    strategy:
+      fail-fast: false
+      matrix:
+        operating-system:
+          - "ubuntu-latest"
+          - "macos-latest"
+        php-versions:
+          - "7.0"
+          - "7.1"
+          - "7.2"
+          - "7.3"
+          - "7.4"
+          - "8.0"
+          - "8.1"
+          - "8.2"
+          - "8.3"
+          - "8.4"
+          - "8.5"
+          - "nightly"
+    steps:
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          coverage: none
+          tools: phpize
+        env:
+          update: true
+
+      - uses: actions/checkout@v3
+
+      - name: Setup extension
+        run: |
+          phpize
+          ./configure --enable-scalar-objects
+          make
+          sudo make install
+
+      - name: Make test
+        run: make test
+
+      - name: Run tests
+        env:
+          REPORT_EXIT_STATUS: 1
+        run: php run-tests.php -p `which php` --show-diff -d extension=`pwd`/modules/scalar_objects.so -q
diff --git a/README.md b/README.md
index b3929dd..2a5dcdb 100644
--- a/README.md
+++ b/README.md
@@ -58,8 +58,8 @@ load these APIs just include the `handlers/bootstrap.php` file.
 Installation
 ------------
 
-The master branch supports PHP version 7.0 to 8.0. Use the [version 0.2][version_0_2]
-branch for PHP 5 support.
+The master branch supports PHP version 7.0 to 8.1. The extension is incompatible
+with the JIT compiler.
 
 ### Unix
 
diff --git a/doc/string_api.md b/doc/string_api.md
index 6c4e87e..e597934 100644
--- a/doc/string_api.md
+++ b/doc/string_api.md
@@ -325,6 +325,7 @@ length of the main string is not divisible by the chunk length, then the last ch
 >
  * This function corresponds to `str_split`.
  * It is perfectly valid to have a chunk length that is longer than the main string.
+ * Chunking an empty string results in an empty array.
  * The name `chunk()` was chosen, because `split()` seems more appropriate for the `explode`
    equivalent. Furthermore the corresponding array functionality is also named `chunk()`.
 
diff --git a/handlers/string.php b/handlers/string.php
index 7090dcd..3e49d07 100644
--- a/handlers/string.php
+++ b/handlers/string.php
@@ -125,6 +125,10 @@ public static function split($self, $separator, $limit = PHP_INT_MAX) {
 
     public static function chunk($self, $chunkLength = 1) {
         $self->verifyPositive($chunkLength, 'Chunk length');
+        if ($self === '') {
+            // str_split() prior to PHP 8.2 is buggy and returns [''] instead.
+            return [];
+        }
         return str_split($self, $chunkLength);
     }
 
diff --git a/scalar_objects.c b/scalar_objects.c
index 84cf290..08816a9 100644
--- a/scalar_objects.c
+++ b/scalar_objects.c
@@ -82,10 +82,7 @@ static zval *get_object_zval_ptr_real(
 	int type
 ) {
 	if (op_type == IS_UNUSED) {
-		if (!SO_THIS) {
-			zend_error(E_ERROR, "Using $this when not in object context");
-		}
-
+		ZEND_ASSERT(SO_THIS && "Checked by get_object_zval_ptr_safe() beforehand");
 		return SO_THIS;
 	} else {
 		return get_zval_ptr_real(opline, op_type, node, execute_data, type);
@@ -159,8 +156,15 @@ static zend_function *scalar_objects_get_indirection_func(
 	ind->fn.handler = scalar_objects_indirection_func;
 	ind->fn.scope = ce;
 	ind->fn.fn_flags = ZEND_ACC_CALL_VIA_HANDLER | (fbc->common.fn_flags & keep_flags);
+	ind->fn.fn_flags |= ZEND_ACC_USER_ARG_INFO;
 	ind->fn.num_args = fbc->common.num_args - 1;
 	ind->fn.required_num_args = fbc->common.required_num_args - 1;
+#if PHP_VERSION_ID >= 80000
+	ind->fn.attributes = NULL;
+#endif
+#if PHP_VERSION_ID >= 80200
+	ind->fn.T = 0;
+#endif
 
 	ind->fbc = fbc;
 	if (fbc->common.arg_info) {
diff --git a/tests/named_params.phpt b/tests/named_params.phpt
new file mode 100644
index 0000000..9934392
--- /dev/null
+++ b/tests/named_params.phpt
@@ -0,0 +1,29 @@
+--TEST--
+Named parameters
+--SKIPIF--
+<?php
+if (PHP_VERSION_ID < 80000) die('skip For PHP >= 8.0 only');
+?>
+--FILE--
+<?php
+
+register_primitive_type_handler('string', 'StringHandler');
+
+class StringHandler {
+    public static function test($self, $prefix = '', $suffix = '') {
+        return $prefix . $self . $suffix;
+    }
+}
+
+$string = "Test";
+var_dump($string->test(prefix: "P"));
+var_dump($string->test(suffix: "S"));
+var_dump($string->test(prefix: "P", suffix: "S"));
+var_dump($string->test(suffix: "S", prefix: "P"));
+
+?>
+--EXPECT--
+string(5) "PTest"
+string(5) "TestS"
+string(6) "PTestS"
+string(6) "PTestS"
diff --git a/tests/string.phpt b/tests/string.phpt
index 2cfa1ec..ec61687 100644
--- a/tests/string.phpt
+++ b/tests/string.phpt
@@ -499,9 +499,7 @@ count(""): int(1)
 count("", 0): int(1)
 count("", 0, 0): int(1)
 repeat(3): string(0) ""
-chunk(3): array(1) {
-  [0]=>
-  string(0) ""
+chunk(3): array(0) {
 }
 replace("foo", "bar"): string(0) ""
 replace("foo", "bar", 1): string(0) ""