diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 38856a5..8cdfbc3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,5 +1,8 @@
 name: CI
 
+permissions:
+    contents: read
+
 on:
     push:
         branches: ['*']
@@ -14,7 +17,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                php: [ '7.3', '7.4', '8.0', '8.1', '8.2', '8.3' ]
+                php: [ '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4' ]
                 dependency-version: [ '' ]
                 include:
                     -   php: '7.3'
diff --git a/composer.json b/composer.json
index 55e6bcf..3d15969 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "psr/container": "^1.0|^2.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.0",
+        "phpunit/phpunit": "^9.0 || ^10 || ^11 || ^12",
         "athletic/athletic": "~0.1.8",
         "mnapoli/hard-mode": "~0.3.0"
     },
diff --git a/tests/CallableResolverTest.php b/tests/CallableResolverTest.php
index 26796f6..97b0873 100644
--- a/tests/CallableResolverTest.php
+++ b/tests/CallableResolverTest.php
@@ -27,6 +27,7 @@ public function setUp(): void
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_function()
     {
         $result = $this->resolver->resolve('strlen');
@@ -37,6 +38,7 @@ public function resolves_function()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_namespaced_function()
     {
         $result = $this->resolver->resolve(__NAMESPACE__ . '\foo');
@@ -47,6 +49,7 @@ public function resolves_namespaced_function()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_callable_from_container()
     {
         $callable = function () {
@@ -59,6 +62,7 @@ public function resolves_callable_from_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_invokable_class()
     {
         $callable = new CallableSpy;
@@ -70,6 +74,7 @@ public function resolves_invokable_class()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolve_array_method_call()
     {
         $fixture = new InvokerTestFixture;
@@ -84,6 +89,7 @@ public function resolve_array_method_call()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolve_string_method_call()
     {
         $fixture = new InvokerTestFixture;
@@ -98,6 +104,7 @@ public function resolve_string_method_call()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_array_method_call_with_service()
     {
         $fixture = new InvokerTestFixture;
@@ -112,6 +119,7 @@ public function resolves_array_method_call_with_service()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function resolves_string_method_call_with_service()
     {
         $fixture = new InvokerTestFixture;
@@ -126,6 +134,7 @@ public function resolves_string_method_call_with_service()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function throws_resolving_non_callable_from_container()
     {
         $this->expectExceptionMessage("'foo' is neither a callable nor a valid container entry");
@@ -137,6 +146,7 @@ public function throws_resolving_non_callable_from_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function handles_objects_correctly_in_exception_message()
     {
         $this->expectExceptionMessage('Instance of stdClass is not a callable');
@@ -148,6 +158,7 @@ public function handles_objects_correctly_in_exception_message()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function handles_method_calls_correctly_in_exception_message()
     {
         $this->expectExceptionMessage('stdClass::test() is not a callable');
diff --git a/tests/InvokerTest.php b/tests/InvokerTest.php
index 4294abd..1633c69 100644
--- a/tests/InvokerTest.php
+++ b/tests/InvokerTest.php
@@ -32,6 +32,7 @@ public function setUp(): void
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_closure()
     {
         $callable = new CallableSpy;
@@ -44,6 +45,7 @@ public function should_invoke_closure()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_method()
     {
         $fixture = new InvokerTestFixture;
@@ -56,6 +58,7 @@ public function should_invoke_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function cannot_invoke_unknown_method()
     {
         $this->expectExceptionMessage('Invoker\Test\InvokerTestFixture::bar() is not a callable.');
@@ -66,6 +69,7 @@ public function cannot_invoke_unknown_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function cannot_invoke_magic_method()
     {
         $this->expectExceptionMessage('Invoker\Test\InvokerTestMagicMethodFixture::foo() is not a callable. A __call() or __callStatic() method exists but magic methods are not supported.');
@@ -76,6 +80,7 @@ public function cannot_invoke_magic_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function cannot_invoke_static_magic_method()
     {
         $this->expectExceptionMessage('Invoker\Test\InvokerTestStaticMagicMethodFixture::foo() is not a callable. A __call() or __callStatic() method exists but magic methods are not supported.');
@@ -86,6 +91,7 @@ public function cannot_invoke_static_magic_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_static_method()
     {
         $result = $this->invoker->call([InvokerTestStaticFixture::class, 'foo']);
@@ -96,6 +102,7 @@ public function should_invoke_static_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_static_method_with_scope_resolution_syntax()
     {
         $result = $this->invoker->call('Invoker\Test\InvokerTestStaticFixture::foo');
@@ -106,6 +113,7 @@ public function should_invoke_static_method_with_scope_resolution_syntax()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_return_the_callable_return_value()
     {
         $result = $this->invoker->call(function () {
@@ -118,6 +126,7 @@ public function should_return_the_callable_return_value()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_no_value_for_parameter()
     {
         $this->expectExceptionMessage('Unable to invoke the callable because no value was given for parameter 2 ($bar)');
@@ -132,6 +141,7 @@ public function should_throw_if_no_value_for_parameter()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_no_value_for_parameter_even_with_trailing_optional_parameters()
     {
         $this->expectExceptionMessage('Unable to invoke the callable because no value was given for parameter 2 ($bar)');
@@ -146,6 +156,7 @@ public function should_throw_if_no_value_for_parameter_even_with_trailing_option
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_callable_with_parameters_indexed_by_position()
     {
         $callable = new CallableSpy;
@@ -158,6 +169,7 @@ public function should_invoke_callable_with_parameters_indexed_by_position()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_callable_with_parameters_indexed_by_name()
     {
         $parameters = [
@@ -175,6 +187,7 @@ public function should_invoke_callable_with_parameters_indexed_by_name()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_callable_with_default_value_for_undefined_parameters()
     {
         $parameters = [
@@ -192,6 +205,7 @@ public function should_invoke_callable_with_default_value_for_undefined_paramete
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_callable_with_null_for_nullable_parameters()
     {
         $result = $this->invoker->call(function (?string $baz = null) {
@@ -238,6 +252,7 @@ public function should_invoke_callable_with_optional_parameter_before_required_p
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_do_dependency_injection_with_typehint_container_resolver()
     {
         $resolver = new TypeHintContainerResolver($this->container);
@@ -256,6 +271,7 @@ public function should_do_dependency_injection_with_typehint_container_resolver(
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_do_dependency_injection_with_parameter_name_container_resolver()
     {
         $resolver = new ParameterNameContainerResolver($this->container);
@@ -274,6 +290,7 @@ public function should_do_dependency_injection_with_parameter_name_container_res
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_callable_from_container()
     {
         $callable = new CallableSpy;
@@ -287,6 +304,7 @@ public function should_resolve_callable_from_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_array_callable_from_container()
     {
         $fixture = new InvokerTestFixture;
@@ -301,6 +319,7 @@ public function should_resolve_array_callable_from_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_callable_from_container_with_scope_resolution_syntax()
     {
         $fixture = new InvokerTestFixture;
@@ -315,6 +334,7 @@ public function should_resolve_callable_from_container_with_scope_resolution_syn
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_array_callable_from_container_with_class_name()
     {
         $fixture = new InvokerTestFixture;
@@ -329,6 +349,7 @@ public function should_resolve_array_callable_from_container_with_class_name()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_callable_from_container_with_class_name_in_scope_resolution_syntax()
     {
         $fixture = new InvokerTestFixture;
@@ -366,6 +387,7 @@ public function positioned_parameters_have_the_highest_priority()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_not_invoke_statically_a_non_static_method()
     {
         $this->expectExceptionMessage('Cannot call foo() on Invoker\Test\InvokerTestFixture because it is not a class nor a valid container entry');
@@ -376,6 +398,7 @@ public function should_not_invoke_statically_a_non_static_method()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_calling_non_callable_without_container()
     {
         $this->expectExceptionMessage("'foo' is not a callable");
@@ -387,6 +410,7 @@ public function should_throw_if_calling_non_callable_without_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_calling_non_callable_without_container_2()
     {
         $this->expectExceptionMessage('NULL is not a callable');
@@ -398,6 +422,7 @@ public function should_throw_if_calling_non_callable_without_container_2()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_calling_non_callable_with_container()
     {
         $this->expectExceptionMessage("'foo' is neither a callable nor a valid container entry");
@@ -409,6 +434,7 @@ public function should_throw_if_calling_non_callable_with_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_calling_non_callable_object()
     {
         $this->expectExceptionMessage('Instance of stdClass is not a callable');
@@ -420,6 +446,7 @@ public function should_throw_if_calling_non_callable_object()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_static_method_rather_than_resolving_entry_from_container()
     {
         // Register a non-callable so that test fails if we try to invoke that
@@ -434,6 +461,7 @@ public function should_invoke_static_method_rather_than_resolving_entry_from_con
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_no_value_for_optional_parameter_1()
     {
         $this->expectExceptionMessage('Unable to invoke the callable because no value was given for parameter 2 ($bar)');
@@ -449,6 +477,7 @@ public function should_throw_if_no_value_for_optional_parameter_1()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_throw_if_no_value_for_optional_parameter_2()
     {
         $this->expectExceptionMessage('Unable to invoke the callable because no value was given for parameter 2 ($bar)');
@@ -465,6 +494,7 @@ public function should_throw_if_no_value_for_optional_parameter_2()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_invoke_callable_with_variadic_parameter()
     {
         $callable = function (...$param) {
@@ -533,4 +563,3 @@ public static function __callStatic(string $name, array $args): string
         throw new Exception('Unknown method');
     }
 }
-
diff --git a/tests/ParameterResolver/Container/ParameterNameContainerResolverTest.php b/tests/ParameterResolver/Container/ParameterNameContainerResolverTest.php
index e18f430..51af9ad 100644
--- a/tests/ParameterResolver/Container/ParameterNameContainerResolverTest.php
+++ b/tests/ParameterResolver/Container/ParameterNameContainerResolverTest.php
@@ -23,6 +23,7 @@ public function setUp(): void
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_parameter_with_parameter_name_from_container()
     {
         $callable = function ($foo) {
@@ -40,6 +41,7 @@ public function should_resolve_parameter_with_parameter_name_from_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_container_cannot_provide_parameter()
     {
         $callable = function ($foo) {
@@ -54,6 +56,7 @@ public function should_skip_parameter_if_container_cannot_provide_parameter()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_already_resolved()
     {
         $callable = function ($foo) {
diff --git a/tests/ParameterResolver/Container/TypeHintContainerResolverTest.php b/tests/ParameterResolver/Container/TypeHintContainerResolverTest.php
index 3f849f6..bdc9424 100644
--- a/tests/ParameterResolver/Container/TypeHintContainerResolverTest.php
+++ b/tests/ParameterResolver/Container/TypeHintContainerResolverTest.php
@@ -25,6 +25,7 @@ public function setUp(): void
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_parameter_with_typehint_and_container()
     {
         $callable = function (TypeHintContainerResolverFixture $foo, self $bar) {
@@ -45,6 +46,7 @@ public function should_resolve_parameter_with_typehint_and_container()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_container_cannot_provide_typehint()
     {
         $callable = function (TypeHintContainerResolverFixture $foo) {
@@ -59,6 +61,7 @@ public function should_skip_parameter_if_container_cannot_provide_typehint()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_already_resolved()
     {
         $callable = function (TypeHintContainerResolverFixture $foo) {
diff --git a/tests/ParameterResolver/TypeHintResolverTest.php b/tests/ParameterResolver/TypeHintResolverTest.php
index a0f980e..54ac8ff 100644
--- a/tests/ParameterResolver/TypeHintResolverTest.php
+++ b/tests/ParameterResolver/TypeHintResolverTest.php
@@ -20,6 +20,7 @@ public function setUp(): void
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_resolve_parameter_with_typehint()
     {
         $callable = function (TypeHintResolverFixture $foo, self $bar) {
@@ -41,6 +42,7 @@ public function should_resolve_parameter_with_typehint()
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_provided_parameters_do_not_contain_typehint()
     {
         $callable = function (TypeHintResolverFixture $foo) {
@@ -55,6 +57,7 @@ public function should_skip_parameter_if_provided_parameters_do_not_contain_type
     /**
      * @test
      */
+    #[\PHPUnit\Framework\Attributes\Test]
     public function should_skip_parameter_if_already_resolved()
     {
         $callable = function (TypeHintResolverFixture $foo) {