diff --git a/.github/workflows/ci-scheduled.yml b/.github/workflows/ci-scheduled.yml
index df8460c..0189d76 100644
--- a/.github/workflows/ci-scheduled.yml
+++ b/.github/workflows/ci-scheduled.yml
@@ -1,18 +1,18 @@
 name: CI (scheduled)
 on:
   schedule:
-  - cron: 0 14 * * 0 # Sunday 2PM UTC = Monday 12AM AEST
+  - cron: * 14 * * 0 # Every day 2PM UTC = Monday 12AM AEST
 jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.4', '8.0', '8.1']
+        php: ['8.2', '8.3', '8.4', '8.5']
     name: PHP ${{ matrix.php }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v1
+      uses: actions/checkout@v4
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
       with:
@@ -22,13 +22,11 @@ jobs:
     - name: Check PHP version
       run: php -v
     - name: Install dependencies
-      run: make vendor
-    - name: Make
-      if: ${{ startsWith(matrix.php, '7.') }}
-      run: make ci
-    - name: Make
-      if: ${{ startsWith(matrix.php, '8.') }}
-      run: make artifacts/coverage/phpunit/clover.xml
+      run: composer install --no-interaction --prefer-dist
+    - name: Run tests with coverage
+      run: |
+        mkdir -p artifacts/test artifacts/coverage/phpunit
+        vendor/bin/phpunit -c phpunit.xml --coverage-clover artifacts/coverage/phpunit/clover.xml
     - name: Publish coverage
       if: success()
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v4
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1cfc297..671bc4c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,11 +8,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.4', '8.0', '8.1']
+        php: ['8.2', '8.3', '8.4', '8.5']
     name: PHP ${{ matrix.php }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v1
+      uses: actions/checkout@v4
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
       with:
@@ -22,13 +22,11 @@ jobs:
     - name: Check PHP version
       run: php -v
     - name: Install dependencies
-      run: make vendor
-    - name: Make
-      if: ${{ startsWith(matrix.php, '7.') }}
-      run: make ci
-    - name: Make
-      if: ${{ startsWith(matrix.php, '8.') }}
-      run: make artifacts/coverage/phpunit/clover.xml
+      run: composer install --no-interaction --prefer-dist
+    - name: Run tests with coverage
+      run: |
+        mkdir -p artifacts/test artifacts/coverage/phpunit
+        vendor/bin/phpunit -c phpunit.xml --coverage-clover artifacts/coverage/phpunit/clover.xml
     - name: Publish coverage
       if: success()
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v4
diff --git a/.idea/phpunit.xml b/.idea/phpunit.xml
new file mode 100644
index 0000000..4ea9753
--- /dev/null
+++ b/.idea/phpunit.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="PHPUnit">
+    <option name="directories">
+      <list>
+        <option value="$PROJECT_DIR$/test" />
+      </list>
+    </option>
+  </component>
+</project>
\ No newline at end of file
diff --git a/README.md b/README.md
index 27cd915..df37efc 100644
--- a/README.md
+++ b/README.md
@@ -1,16 +1,13 @@
-> # No longer maintained
->
-> This package is no longer maintained. See [this statement] for more info.
->
-> [this statement]: https://gist.github.com/ezzatron/713a548735febe3d76f8ca831bc895c0
-
 # Pops
 
 *PHP Object Proxy System.*
 
+This is a maintained fork of [eloquent/pops] originally created by Erin Millard.
+
 ## Installation and documentation
 
-* Available as [Composer] package [eloquent/pops].
+* Available as [Composer] package `vedavith/pops-fork` (maintained fork of `eloquent/pops`).
+* Requires PHP 8.2 or later.
 
 ## What is *Pops*?
 
@@ -45,12 +42,12 @@ use Eloquent\Pops\ProxyObject;
 
 class UppercaseProxyObject extends ProxyObject
 {
-    public function popsCall($method, array &$arguments)
+    public function popsCall(string $method, array &$arguments): mixed
     {
         return strtoupper(parent::popsCall($method, $arguments));
     }
 
-    public function __get($property)
+    public function __get(string $property): mixed
     {
         return strtoupper(parent::__get($property));
     }
@@ -148,7 +145,7 @@ class OutputEscaperProxyArray extends ProxyArray
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
@@ -170,7 +167,7 @@ class OutputEscaperProxyClass extends ProxyClass
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
@@ -192,7 +189,7 @@ class OutputEscaperProxyObject extends ProxyObject
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
@@ -214,7 +211,7 @@ class OutputEscaperProxyPrimitive extends ProxyPrimitive
      *
      * @return string The HTML-secaped version of this primitive.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return htmlspecialchars(
             strval($this->popsValue()),
diff --git a/composer.json b/composer.json
index 5bd9680..8432aa5 100644
--- a/composer.json
+++ b/composer.json
@@ -1,24 +1,37 @@
 {
-    "name": "eloquent/pops",
-    "description": "PHP object proxy system.",
+    "name": "vedavith/pops-fork",
+    "description": "Maintained fork of eloquent/pops, a PHP object proxy system.",
     "keywords": ["object", "proxy", "method", "property"],
-    "homepage": "https://github.com/eloquent/pops",
+    "homepage": "https://github.com/vedavith/pops-fork",
     "license": "MIT",
+    "support": {
+        "issues": "https://github.com/vedavith/pops-fork/issues",
+        "source": "https://github.com/vedavith/pops-fork"
+    },
+    "replace": {
+        "eloquent/pops": "self.version"
+    },
     "authors": [
         {
             "name": "Erin Millard",
             "email": "ezzatron@gmail.com",
             "homepage": "http://ezzatron.com/"
+        },
+        {
+            "name": "Vedavith Ravula",
+            "email": "veda_ravula@outlook.com"
         }
     ],
     "require": {
-        "php": "^7.4 || ^8"
+        "php": "^8.2"
     },
     "require-dev": {
         "eloquent/code-style": "^2",
         "errors/exceptions": "^0.2",
         "friendsofphp/php-cs-fixer": "^3",
-        "phpunit/phpunit": "^9"
+        "phpunit/phpunit": "^11.3 || ^12",
+        "ext-mbstring": "*",
+        "phpunit/php-code-coverage": "^11 || ^12"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml b/phpunit.xml
index 1edbdca..2a29e12 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,12 +1,9 @@
 <phpunit
     bootstrap="vendor/autoload.php"
-    cacheResultFile="artifacts/test/phpunit.result.cache"
     colors="true"
     beStrictAboutChangesToGlobalState="true"
     beStrictAboutOutputDuringTests="true"
     beStrictAboutTestsThatDoNotTestAnything="true"
-    convertErrorsToExceptions="true"
-    verbose="true"
 >
     <testsuites>
         <testsuite name="main">
@@ -18,11 +15,13 @@
         <report>
             <text outputFile="php://stdout" showOnlySummary="true"/>
         </report>
+    </coverage>
 
+    <source>
         <include>
             <directory>src</directory>
         </include>
-    </coverage>
+    </source>
 
     <php>
         <ini name="error_reporting" value="-1"/>
diff --git a/src/AbstractProxy.php b/src/AbstractProxy.php
index 64c6d95..ae6f06e 100644
--- a/src/AbstractProxy.php
+++ b/src/AbstractProxy.php
@@ -23,7 +23,7 @@ abstract class AbstractProxy implements ProxyInterface
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    public function __construct($value)
+    public function __construct(mixed $value)
     {
         $this->setPopsValue($value);
     }
@@ -35,7 +35,7 @@ public function __construct($value)
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    public function setPopsValue($value)
+    public function setPopsValue(mixed $value): void
     {
         $this->assertPopsValue($value);
 
@@ -47,7 +47,7 @@ public function setPopsValue($value)
      *
      * @return mixed The wrapped value.
      */
-    public function popsValue()
+    public function popsValue(): mixed
     {
         return $this->value;
     }
@@ -60,7 +60,7 @@ public function popsValue()
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    abstract protected function assertPopsValue($value);
+    abstract protected function assertPopsValue(mixed $value): void;
 
-    private $value;
+    private mixed $value;
 }
diff --git a/src/AbstractTraversableProxy.php b/src/AbstractTraversableProxy.php
index 445e3d9..5c33e16 100644
--- a/src/AbstractTraversableProxy.php
+++ b/src/AbstractTraversableProxy.php
@@ -27,7 +27,7 @@ abstract class AbstractTraversableProxy extends AbstractProxy implements
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    public function __construct($value, $isRecursive = null)
+    public function __construct(mixed $value, ?bool $isRecursive = null)
     {
         if (null === $isRecursive) {
             $isRecursive = false;
@@ -43,7 +43,7 @@ public function __construct($value, $isRecursive = null)
      *
      * @return bool True if the wrapped value is recursively proxied.
      */
-    public function isPopsRecursive()
+    public function isPopsRecursive(): bool
     {
         return $this->isPopsRecursive;
     }
@@ -53,8 +53,7 @@ public function isPopsRecursive()
      *
      * @return mixed The current value.
      */
-    #[\ReturnTypeWillChange]
-    public function current()
+    public function current(): mixed
     {
         return $this->popsProxySubValue($this->popsInnerIterator()->current());
     }
@@ -64,8 +63,7 @@ public function current()
      *
      * @return mixed The current key.
      */
-    #[\ReturnTypeWillChange]
-    public function key()
+    public function key(): mixed
     {
         return $this->popsInnerIterator()->key();
     }
@@ -103,7 +101,7 @@ public function valid(): bool
      *
      * @return mixed The proxied value, or the untouched value.
      */
-    protected function popsProxySubValue($value)
+    protected function popsProxySubValue(mixed $value): mixed
     {
         if ($this->isPopsRecursive()) {
             $popsClass = static::popsProxyClass();
@@ -119,7 +117,7 @@ protected function popsProxySubValue($value)
      *
      * @return Iterator An iterator for the wrapped object.
      */
-    protected function popsInnerIterator()
+    protected function popsInnerIterator(): Iterator
     {
         if (null === $this->popsInnerIterator) {
             $this->popsInnerIterator = $this->popsCreateInnerIterator();
@@ -133,8 +131,8 @@ protected function popsInnerIterator()
      *
      * @return Iterator An iterator for the wrapped object.
      */
-    abstract protected function popsCreateInnerIterator();
+    abstract protected function popsCreateInnerIterator(): Iterator;
 
-    private $isPopsRecursive;
-    private $popsInnerIterator;
+    private bool $isPopsRecursive;
+    private ?Iterator $popsInnerIterator = null;
 }
diff --git a/src/ProxyArray.php b/src/ProxyArray.php
index 3dab6e0..176595e 100644
--- a/src/ProxyArray.php
+++ b/src/ProxyArray.php
@@ -27,7 +27,7 @@ class ProxyArray extends AbstractTraversableProxy implements ProxyArrayInterface
      *
      * @return array The wrapped array.
      */
-    public function popsArray()
+    public function popsArray(): array
     {
         return $this->popsValue();
     }
@@ -38,7 +38,7 @@ public function popsArray()
      * @param int|string $index The index to set.
      * @param mixed      $value The new value.
      */
-    public function offsetSet($index, $value): void
+    public function offsetSet(mixed $index, mixed $value): void
     {
         $array = $this->popsValue();
         $array[$index] = $value;
@@ -53,8 +53,7 @@ public function offsetSet($index, $value): void
      *
      * @return mixed The value.
      */
-    #[\ReturnTypeWillChange]
-    public function offsetGet($index)
+    public function offsetGet(mixed $index): mixed
     {
         $array = $this->popsValue();
 
@@ -68,7 +67,7 @@ public function offsetGet($index)
      *
      * @return bool True if the index exists.
      */
-    public function offsetExists($index): bool
+    public function offsetExists(mixed $index): bool
     {
         $array = $this->popsValue();
 
@@ -80,7 +79,7 @@ public function offsetExists($index): bool
      *
      * @param int|string $index The index to remove.
      */
-    public function offsetUnset($index): void
+    public function offsetUnset(mixed $index): void
     {
         $array = $this->popsValue();
         unset($array[$index]);
@@ -103,7 +102,7 @@ public function count(): int
      *
      * @return string The string representation.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return strval($this->popsProxySubValue(strval($this->popsValue())));
     }
@@ -113,7 +112,7 @@ public function __toString()
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\Proxy';
     }
@@ -126,7 +125,7 @@ protected static function popsProxyClass()
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    protected function assertPopsValue($value)
+    protected function assertPopsValue(mixed $value): void
     {
         if (!is_array($value)) {
             throw new Exception\InvalidTypeException($value, 'array');
@@ -138,7 +137,7 @@ protected function assertPopsValue($value)
      *
      * @return Iterator An iterator for the wrapped object.
      */
-    protected function popsCreateInnerIterator()
+    protected function popsCreateInnerIterator(): Iterator
     {
         return new ArrayIterator($this->popsValue());
     }
diff --git a/src/ProxyClass.php b/src/ProxyClass.php
index b2443c5..62593c6 100644
--- a/src/ProxyClass.php
+++ b/src/ProxyClass.php
@@ -26,7 +26,7 @@ class ProxyClass extends AbstractProxy implements ProxyClassInterface
      *
      * @return mixed The result of the method call.
      */
-    public static function __callStatic($method, array $arguments)
+    public static function __callStatic(string $method, array $arguments): mixed
     {
         return static::popsProxySubValue(
             call_user_func_array(
@@ -42,7 +42,7 @@ public static function __callStatic($method, array $arguments)
      *
      * @return ProxyClass The non-static class proxy.
      */
-    public static function popsProxy()
+    public static function popsProxy(): ProxyClass
     {
         $originalClass = static::$popsStaticOriginalClass;
         if (null === $originalClass) {
@@ -73,10 +73,10 @@ public static function popsProxy()
      * @return string The class name used for the proxy class.
      */
     public static function popsGenerateStaticClassProxy(
-        $class,
-        $isRecursive = null,
-        $proxyClass = null
-    ) {
+        string $class,
+        ?bool $isRecursive = null,
+        ?string $proxyClass = null
+    ): string {
         if (null === $isRecursive) {
             $isRecursive = false;
         }
@@ -99,7 +99,7 @@ public static function popsGenerateStaticClassProxy(
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    public function __construct($class, $isRecursive = null)
+    public function __construct(string $class, ?bool $isRecursive = null)
     {
         if (null === $isRecursive) {
             $isRecursive = false;
@@ -118,7 +118,7 @@ public function __construct($class, $isRecursive = null)
      *
      * @return string The proxied class name.
      */
-    public function popsClass()
+    public function popsClass(): string
     {
         return $this->popsValue();
     }
@@ -128,7 +128,7 @@ public function popsClass()
      *
      * @return bool True if the wrapped class is recursively proxied.
      */
-    public function isPopsRecursive()
+    public function isPopsRecursive(): bool
     {
         return $this->isPopsRecursive;
     }
@@ -142,7 +142,7 @@ public function isPopsRecursive()
      *
      * @return mixed The result of the method call.
      */
-    public function popsCall($method, array &$arguments)
+    public function popsCall(string $method, array &$arguments): mixed
     {
         return static::popsProxySubValue(
             call_user_func_array(
@@ -161,7 +161,7 @@ public function popsCall($method, array &$arguments)
      *
      * @return mixed The result of the method call.
      */
-    public function __call($method, array $arguments)
+    public function __call(string $method, array $arguments): mixed
     {
         return $this->popsCall($method, $arguments);
     }
@@ -172,7 +172,7 @@ public function __call($method, array $arguments)
      * @param string $property The name of the property to set.
      * @param mixed  $value    The new value.
      */
-    public function __set($property, $value)
+    public function __set(string $property, mixed $value): void
     {
         $class = $this->popsValue();
         $class::$$property = $value;
@@ -185,7 +185,7 @@ public function __set($property, $value)
      *
      * @return mixed The value of the property.
      */
-    public function __get($property)
+    public function __get(string $property): mixed
     {
         $class = $this->popsValue();
 
@@ -202,7 +202,7 @@ public function __get($property)
      *
      * @return bool True if the property exists.
      */
-    public function __isset($property)
+    public function __isset(string $property): bool
     {
         $class = $this->popsValue();
 
@@ -214,7 +214,7 @@ public function __isset($property)
      *
      * @param string $property The name of the property to set.
      */
-    public function __unset($property)
+    public function __unset(string $property): void
     {
         $class = $this->popsValue();
 
@@ -226,7 +226,7 @@ public function __unset($property)
      *
      * @return string The string representation.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->popsValue();
     }
@@ -236,7 +236,7 @@ public function __toString()
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\Proxy';
     }
@@ -249,7 +249,7 @@ protected static function popsProxyClass()
      *
      * @return mixed The proxied value, or the untouched value.
      */
-    protected static function popsProxySubValue($value, $isRecursive)
+    protected static function popsProxySubValue(mixed $value, bool $isRecursive): mixed
     {
         if ($isRecursive) {
             $popsProxyClass = static::popsProxyClass();
@@ -263,17 +263,17 @@ protected static function popsProxySubValue($value, $isRecursive)
     /**
      * Generate a static class proxy definition.
      *
-     * @param string      $class       The name of the class to proxy.
+     * @param string      $originalClass The name of the class to proxy.
      * @param bool        $isRecursive True if the proxy should be recursive.
      * @param string|null &$proxyClass The class name to use for the proxy class.
      *
      * @return string The proxy class definition.
      */
     protected static function popsStaticClassProxyDefinition(
-        $originalClass,
-        $isRecursive,
-        &$proxyClass
-    ) {
+        string $originalClass,
+        bool $isRecursive,
+        ?string &$proxyClass
+    ): string {
         $proxyClass = static::popsStaticClassProxyDefinitionProxyClass(
             $originalClass,
             $proxyClass
@@ -298,9 +298,9 @@ protected static function popsStaticClassProxyDefinition(
      * @return string The proxy class name.
      */
     protected static function popsStaticClassProxyDefinitionProxyClass(
-        $originalClass,
-        $proxyClass
-    ) {
+        string $originalClass,
+        ?string $proxyClass
+    ): string {
         if (null === $proxyClass) {
             $originalClassParts = explode('\\', $originalClass);
             $proxyClassPrefix = array_pop($originalClassParts) . '_Pops_';
@@ -325,7 +325,7 @@ protected static function popsStaticClassProxyDefinitionProxyClass(
      *
      * @return string The static class proxy class header.
      */
-    protected static function popsStaticClassProxyDefinitionHeader($proxyClass)
+    protected static function popsStaticClassProxyDefinitionHeader(string $proxyClass): string
     {
         $proxyClassParts = explode('\\', $proxyClass);
         $proxyClass = array_pop($proxyClassParts);
@@ -356,12 +356,12 @@ protected static function popsStaticClassProxyDefinitionHeader($proxyClass)
      * @return string The static class proxy class body.
      */
     protected static function popsStaticClassProxyDefinitionBody(
-        $originalClass,
-        $isRecursive
-    ) {
+        string $originalClass,
+        bool $isRecursive
+    ): string {
         return sprintf(
-            'protected static $popsStaticOriginalClass = %s; ' .
-                'protected static $isPopsStaticRecursive = %s;',
+            'protected static ?string $popsStaticOriginalClass = %s; ' .
+                'protected static bool $isPopsStaticRecursive = %s;',
             var_export($originalClass, true),
             var_export($isRecursive, true)
         );
@@ -375,15 +375,15 @@ protected static function popsStaticClassProxyDefinitionBody(
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    protected function assertPopsValue($value)
+    protected function assertPopsValue(mixed $value): void
     {
         if (!class_exists($value)) {
             throw new Exception\InvalidTypeException($value, 'class name');
         }
     }
 
-    protected static $popsStaticOriginalClass;
-    protected static $isPopsStaticRecursive;
-    private static $popsStaticProxies = [];
-    private $isPopsRecursive;
+    protected static ?string $popsStaticOriginalClass = null;
+    protected static bool $isPopsStaticRecursive = false;
+    private static array $popsStaticProxies = [];
+    private bool $isPopsRecursive;
 }
diff --git a/src/ProxyClassInterface.php b/src/ProxyClassInterface.php
index f60dda8..2beab83 100644
--- a/src/ProxyClassInterface.php
+++ b/src/ProxyClassInterface.php
@@ -21,7 +21,7 @@ interface ProxyClassInterface extends ProxyInterface
      *
      * @return bool True if the wrapped class is recursively proxied.
      */
-    public function isPopsRecursive();
+    public function isPopsRecursive(): bool;
 
     /**
      * Call a static method on the proxied class with support for by-reference
@@ -32,7 +32,7 @@ public function isPopsRecursive();
      *
      * @return mixed The result of the method call.
      */
-    public function popsCall($method, array &$arguments);
+    public function popsCall(string $method, array &$arguments): mixed;
 
     /**
      * Call a static method on the proxied class.
@@ -42,7 +42,7 @@ public function popsCall($method, array &$arguments);
      *
      * @return mixed The result of the method call.
      */
-    public function __call($method, array $arguments);
+    public function __call(string $method, array $arguments): mixed;
 
     /**
      * Set the value of a static property on the proxied class.
@@ -50,7 +50,7 @@ public function __call($method, array $arguments);
      * @param string $property The name of the property to set.
      * @param mixed  $value    The new value.
      */
-    public function __set($property, $value);
+    public function __set(string $property, mixed $value): void;
 
     /**
      * Get the value of a static property on the proxied class.
@@ -59,7 +59,7 @@ public function __set($property, $value);
      *
      * @return mixed The value of the property.
      */
-    public function __get($property);
+    public function __get(string $property): mixed;
 
     /**
      * Returns true if the supplied static property exists on the proxied class.
@@ -68,12 +68,12 @@ public function __get($property);
      *
      * @return bool True if the property exists.
      */
-    public function __isset($property);
+    public function __isset(string $property): bool;
 
     /**
      * Set the value of a static property on the proxied class to null.
      *
      * @param string $property The name of the property to set.
      */
-    public function __unset($property);
+    public function __unset(string $property): void;
 }
diff --git a/src/ProxyInterface.php b/src/ProxyInterface.php
index 8033e90..a34d889 100644
--- a/src/ProxyInterface.php
+++ b/src/ProxyInterface.php
@@ -23,19 +23,19 @@ interface ProxyInterface
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    public function setPopsValue($value);
+    public function setPopsValue(mixed $value): void;
 
     /**
      * Get the wrapped value.
      *
      * @return mixed The wrapped value.
      */
-    public function popsValue();
+    public function popsValue(): mixed;
 
     /**
      * Get the string representation of this value.
      *
      * @return string The string representation.
      */
-    public function __toString();
+    public function __toString(): string;
 }
diff --git a/src/ProxyObject.php b/src/ProxyObject.php
index d5efeb8..d5d6d2e 100644
--- a/src/ProxyObject.php
+++ b/src/ProxyObject.php
@@ -29,7 +29,7 @@ class ProxyObject extends AbstractTraversableProxy implements
      *
      * @return object The wrapped object.
      */
-    public function popsObject()
+    public function popsObject(): object
     {
         return $this->popsValue();
     }
@@ -43,7 +43,7 @@ public function popsObject()
      *
      * @return mixed The result of the method call.
      */
-    public function popsCall($method, array &$arguments)
+    public function popsCall(string $method, array &$arguments): mixed
     {
         return $this->popsProxySubValue(
             call_user_func_array([$this->popsValue(), $method], $arguments)
@@ -58,7 +58,7 @@ public function popsCall($method, array &$arguments)
      *
      * @return mixed The result of the method call.
      */
-    public function __call($method, array $arguments)
+    public function __call(string $method, array $arguments): mixed
     {
         return $this->popsCall($method, $arguments);
     }
@@ -68,7 +68,7 @@ public function __call($method, array $arguments)
      *
      * @return mixed The result of invocation.
      */
-    public function __invoke()
+    public function __invoke(): mixed
     {
         return $this->__call('__invoke', func_get_args());
     }
@@ -79,7 +79,7 @@ public function __invoke()
      * @param string $property The property name.
      * @param mixed  $value    The new value.
      */
-    public function __set($property, $value)
+    public function __set(string $property, mixed $value): void
     {
         $this->popsValue()->$property = $value;
     }
@@ -91,7 +91,7 @@ public function __set($property, $value)
      *
      * @return mixed The property value.
      */
-    public function __get($property)
+    public function __get(string $property): mixed
     {
         return $this->popsProxySubValue($this->popsValue()->$property);
     }
@@ -103,7 +103,7 @@ public function __get($property)
      *
      * @return bool True if the property exists.
      */
-    public function __isset($property)
+    public function __isset(string $property): bool
     {
         return isset($this->popsValue()->$property);
     }
@@ -113,7 +113,7 @@ public function __isset($property)
      *
      * @param string $property The property name.
      */
-    public function __unset($property)
+    public function __unset(string $property): void
     {
         unset($this->popsValue()->$property);
     }
@@ -124,7 +124,7 @@ public function __unset($property)
      * @param string $key   The key to set.
      * @param mixed  $value The new value.
      */
-    public function offsetSet($key, $value): void
+    public function offsetSet(mixed $key, mixed $value): void
     {
         $this->__call('offsetSet', func_get_args());
     }
@@ -136,8 +136,7 @@ public function offsetSet($key, $value): void
      *
      * @return mixed The value.
      */
-    #[\ReturnTypeWillChange]
-    public function offsetGet($key)
+    public function offsetGet(mixed $key): mixed
     {
         return $this->__call('offsetGet', func_get_args());
     }
@@ -150,7 +149,7 @@ public function offsetGet($key)
      *
      * @return bool True if the key exists.
      */
-    public function offsetExists($key): bool
+    public function offsetExists(mixed $key): bool
     {
         return $this->__call('offsetExists', func_get_args());
     }
@@ -160,7 +159,7 @@ public function offsetExists($key): bool
      *
      * @param string $key The key to remove.
      */
-    public function offsetUnset($key): void
+    public function offsetUnset(mixed $key): void
     {
         $this->__call('offsetUnset', func_get_args());
     }
@@ -180,7 +179,7 @@ public function count(): int
      *
      * @return string The string representation.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return strval($this->__call('__toString', []));
     }
@@ -190,7 +189,7 @@ public function __toString()
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\Proxy';
     }
@@ -203,7 +202,7 @@ protected static function popsProxyClass()
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    protected function assertPopsValue($value)
+    protected function assertPopsValue(mixed $value): void
     {
         if (!is_object($value)) {
             throw new Exception\InvalidTypeException($value, 'object');
@@ -215,7 +214,7 @@ protected function assertPopsValue($value)
      *
      * @return Iterator An iterator for the wrapped object.
      */
-    protected function popsCreateInnerIterator()
+    protected function popsCreateInnerIterator(): Iterator
     {
         if ($this->popsValue() instanceof Iterator) {
             $iterator = $this->popsValue();
diff --git a/src/ProxyObjectInterface.php b/src/ProxyObjectInterface.php
index 2cc7217..46b05fc 100644
--- a/src/ProxyObjectInterface.php
+++ b/src/ProxyObjectInterface.php
@@ -33,7 +33,7 @@ interface ProxyObjectInterface extends
      *
      * @return mixed The result of the method call.
      */
-    public function popsCall($method, array &$arguments);
+    public function popsCall(string $method, array &$arguments): mixed;
 
     /**
      * Call a method on the wrapped object.
@@ -43,14 +43,14 @@ public function popsCall($method, array &$arguments);
      *
      * @return mixed The result of the method call.
      */
-    public function __call($method, array $arguments);
+    public function __call(string $method, array $arguments): mixed;
 
     /**
      * Invoke this object.
      *
      * @return mixed The result of invocation.
      */
-    public function __invoke();
+    public function __invoke(): mixed;
 
     /**
      * Set the value of a property on the wrapped object.
@@ -58,7 +58,7 @@ public function __invoke();
      * @param string $property The property name.
      * @param mixed  $value    The new value.
      */
-    public function __set($property, $value);
+    public function __set(string $property, mixed $value): void;
 
     /**
      * Get the value of a property from the wrapped object.
@@ -67,7 +67,7 @@ public function __set($property, $value);
      *
      * @return mixed The property value.
      */
-    public function __get($property);
+    public function __get(string $property): mixed;
 
     /**
      * Returns true if the property exists on the wrapped object.
@@ -76,12 +76,12 @@ public function __get($property);
      *
      * @return bool True if the property exists.
      */
-    public function __isset($property);
+    public function __isset(string $property): bool;
 
     /**
      * Unset a property from the wrapped object.
      *
      * @param string $property The property name.
      */
-    public function __unset($property);
+    public function __unset(string $property): void;
 }
diff --git a/src/ProxyPrimitive.php b/src/ProxyPrimitive.php
index 2da59b4..6ac9fb2 100644
--- a/src/ProxyPrimitive.php
+++ b/src/ProxyPrimitive.php
@@ -24,7 +24,7 @@ class ProxyPrimitive extends AbstractProxy implements ProxyPrimitiveInterface
      *
      * @return scalar|null The wrapped value.
      */
-    public function popsPrimitive()
+    public function popsPrimitive(): mixed
     {
         return $this->popsValue();
     }
@@ -34,7 +34,7 @@ public function popsPrimitive()
      *
      * @return string The string representation.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return strval($this->popsValue());
     }
@@ -47,7 +47,7 @@ public function __toString()
      *
      * @throws Exception\InvalidTypeException If the supplied value is not the correct type.
      */
-    protected function assertPopsValue($value)
+    protected function assertPopsValue(mixed $value): void
     {
         if (!is_scalar($value)) {
             throw new Exception\InvalidTypeException($value, 'scalar|null');
diff --git a/src/Safe/SafeProxyArray.php b/src/Safe/SafeProxyArray.php
index 48ea6ba..61f17a4 100644
--- a/src/Safe/SafeProxyArray.php
+++ b/src/Safe/SafeProxyArray.php
@@ -23,7 +23,7 @@ class SafeProxyArray extends ProxyArray implements SafeInterface
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\SafeProxy';
     }
diff --git a/src/Safe/SafeProxyClass.php b/src/Safe/SafeProxyClass.php
index 652eefc..7ebb562 100644
--- a/src/Safe/SafeProxyClass.php
+++ b/src/Safe/SafeProxyClass.php
@@ -23,7 +23,7 @@ class SafeProxyClass extends ProxyClass implements SafeInterface
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\SafeProxy';
     }
diff --git a/src/Safe/SafeProxyObject.php b/src/Safe/SafeProxyObject.php
index 9dfe705..75f3672 100644
--- a/src/Safe/SafeProxyObject.php
+++ b/src/Safe/SafeProxyObject.php
@@ -23,7 +23,7 @@ class SafeProxyObject extends ProxyObject implements SafeInterface
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\SafeProxy';
     }
diff --git a/src/TraversableProxyInterface.php b/src/TraversableProxyInterface.php
index 7e24210..bea971d 100644
--- a/src/TraversableProxyInterface.php
+++ b/src/TraversableProxyInterface.php
@@ -21,5 +21,5 @@ interface TraversableProxyInterface extends ProxyInterface
      *
      * @return bool True if the wrapped value is recursively proxied.
      */
-    public function isPopsRecursive();
+    public function isPopsRecursive(): bool;
 }
diff --git a/test/src/OutputEscaper/OutputEscaperProxyArray.php b/test/src/OutputEscaper/OutputEscaperProxyArray.php
index 80caa88..4e746c9 100644
--- a/test/src/OutputEscaper/OutputEscaperProxyArray.php
+++ b/test/src/OutputEscaper/OutputEscaperProxyArray.php
@@ -23,7 +23,7 @@ class OutputEscaperProxyArray extends ProxyArray
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
diff --git a/test/src/OutputEscaper/OutputEscaperProxyClass.php b/test/src/OutputEscaper/OutputEscaperProxyClass.php
index f6eb419..f32109a 100644
--- a/test/src/OutputEscaper/OutputEscaperProxyClass.php
+++ b/test/src/OutputEscaper/OutputEscaperProxyClass.php
@@ -23,7 +23,7 @@ class OutputEscaperProxyClass extends ProxyClass
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
diff --git a/test/src/OutputEscaper/OutputEscaperProxyObject.php b/test/src/OutputEscaper/OutputEscaperProxyObject.php
index 17a2f53..ef8601e 100644
--- a/test/src/OutputEscaper/OutputEscaperProxyObject.php
+++ b/test/src/OutputEscaper/OutputEscaperProxyObject.php
@@ -23,7 +23,7 @@ class OutputEscaperProxyObject extends ProxyObject
      *
      * @return string The proxy class.
      */
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\OutputEscaperProxy';
     }
diff --git a/test/src/OutputEscaper/OutputEscaperProxyPrimitive.php b/test/src/OutputEscaper/OutputEscaperProxyPrimitive.php
index e7bbd66..5f1c420 100644
--- a/test/src/OutputEscaper/OutputEscaperProxyPrimitive.php
+++ b/test/src/OutputEscaper/OutputEscaperProxyPrimitive.php
@@ -23,7 +23,7 @@ class OutputEscaperProxyPrimitive extends ProxyPrimitive
      *
      * @return string The HTML-secaped version of this primitive.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return htmlspecialchars(
             strval($this->popsValue()),
diff --git a/test/src/Test/Fixture/ArrayAccess.php b/test/src/Test/Fixture/ArrayAccess.php
index 545469f..f4fbbe1 100644
--- a/test/src/Test/Fixture/ArrayAccess.php
+++ b/test/src/Test/Fixture/ArrayAccess.php
@@ -15,23 +15,22 @@
 
 class ArrayAccess extends Obj implements ArrayAccessInterface
 {
-    public function offsetSet($property, $value): void
+    public function offsetSet(mixed $property, mixed $value): void
     {
         $this->values[$property] = $value;
     }
 
-    #[\ReturnTypeWillChange]
-    public function offsetGet($property)
+    public function offsetGet(mixed $property): mixed
     {
         return $this->values[$property];
     }
 
-    public function offsetExists($property): bool
+    public function offsetExists(mixed $property): bool
     {
         return array_key_exists($property, $this->values);
     }
 
-    public function offsetUnset($property): void
+    public function offsetUnset(mixed $property): void
     {
         unset($this->values[$property]);
     }
diff --git a/test/src/Test/Fixture/Iterator.php b/test/src/Test/Fixture/Iterator.php
index b50aadf..c90108f 100644
--- a/test/src/Test/Fixture/Iterator.php
+++ b/test/src/Test/Fixture/Iterator.php
@@ -22,14 +22,12 @@ public function __construct(array $values)
         $this->iterator = new ArrayIterator($this->values);
     }
 
-    #[\ReturnTypeWillChange]
-    public function current()
+    public function current(): mixed
     {
         return $this->iterator->current();
     }
 
-    #[\ReturnTypeWillChange]
-    public function key()
+    public function key(): mixed
     {
         return $this->iterator->key();
     }
diff --git a/test/src/Test/Fixture/Uppercase/UppercaseProxyArray.php b/test/src/Test/Fixture/Uppercase/UppercaseProxyArray.php
index b7106a3..c330d62 100644
--- a/test/src/Test/Fixture/Uppercase/UppercaseProxyArray.php
+++ b/test/src/Test/Fixture/Uppercase/UppercaseProxyArray.php
@@ -15,7 +15,7 @@
 
 class UppercaseProxyArray extends ProxyArray
 {
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\UppercaseProxy';
     }
diff --git a/test/src/Test/Fixture/Uppercase/UppercaseProxyClass.php b/test/src/Test/Fixture/Uppercase/UppercaseProxyClass.php
index ad52261..f0aaa3e 100644
--- a/test/src/Test/Fixture/Uppercase/UppercaseProxyClass.php
+++ b/test/src/Test/Fixture/Uppercase/UppercaseProxyClass.php
@@ -15,7 +15,7 @@
 
 class UppercaseProxyClass extends ProxyClass
 {
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\UppercaseProxy';
     }
diff --git a/test/src/Test/Fixture/Uppercase/UppercaseProxyObject.php b/test/src/Test/Fixture/Uppercase/UppercaseProxyObject.php
index bbb3464..7c7f84c 100644
--- a/test/src/Test/Fixture/Uppercase/UppercaseProxyObject.php
+++ b/test/src/Test/Fixture/Uppercase/UppercaseProxyObject.php
@@ -15,7 +15,7 @@
 
 class UppercaseProxyObject extends ProxyObject
 {
-    protected static function popsProxyClass()
+    protected static function popsProxyClass(): string
     {
         return __NAMESPACE__ . '\UppercaseProxy';
     }
diff --git a/test/src/Test/Fixture/Uppercase/UppercaseProxyPrimitive.php b/test/src/Test/Fixture/Uppercase/UppercaseProxyPrimitive.php
index 2922a7b..53fdc6e 100644
--- a/test/src/Test/Fixture/Uppercase/UppercaseProxyPrimitive.php
+++ b/test/src/Test/Fixture/Uppercase/UppercaseProxyPrimitive.php
@@ -15,7 +15,7 @@
 
 class UppercaseProxyPrimitive extends ProxyPrimitive
 {
-    public function __toString()
+    public function __toString(): string
     {
         return mb_strtoupper(strval($this->popsValue()));
     }
diff --git a/test/src/UppercaseProxyObject.php b/test/src/UppercaseProxyObject.php
index f45ca68..a5d7b68 100644
--- a/test/src/UppercaseProxyObject.php
+++ b/test/src/UppercaseProxyObject.php
@@ -9,16 +9,18 @@
  * file that was distributed with this source code.
  */
 
+namespace Eloquent\Pops;
+
 use Eloquent\Pops\ProxyObject;
 
 class UppercaseProxyObject extends ProxyObject
 {
-    public function popsCall($method, array &$arguments)
+    public function popsCall(string $method, array &$arguments): mixed
     {
         return strtoupper(parent::popsCall($method, $arguments));
     }
 
-    public function __get($property)
+    public function __get(string $property): mixed
     {
         return strtoupper(parent::__get($property));
     }
diff --git a/test/suite/FunctionalTest.php b/test/suite/FunctionalTest.php
index b9da520..a53dbc7 100644
--- a/test/suite/FunctionalTest.php
+++ b/test/suite/FunctionalTest.php
@@ -11,6 +11,7 @@
 
 use Eloquent\Pops\Proxy;
 use Eloquent\Pops\Safe\SafeProxy;
+use Eloquent\Pops\UppercaseProxyObject;
 use OutputEscaper\OutputEscaperProxy;
 use PHPUnit\Framework\TestCase;