diff --git a/README.md b/README.md
index 115f5fd..d5551d1 100644
--- a/README.md
+++ b/README.md
@@ -97,6 +97,7 @@ These are the available attributes and their corresponding PHPDoc annotations:
 | Attribute                                                                                                         | PHPDoc Annotations        |
 |-------------------------------------------------------------------------------------------------------------------|---------------------------|
 | [Deprecated](https://github.com/php-static-analysis/attributes/blob/main/doc/Deprecated.md)                       | `@deprecated`             |
+| [Internal](https://github.com/php-static-analysis/attributes/blob/main/doc/Internal.md)                           | `@internal`               |
 | [IsReadOnly](https://github.com/php-static-analysis/attributes/blob/main/doc/IsReadOnly.md)                       | `@readonly`               |
 | [Method](https://github.com/php-static-analysis/attributes/blob/main/doc/Method.md)                               | `@method`                 |
 | [Param](https://github.com/php-static-analysis/attributes/blob/main/doc/Param.md)                                 | `@param`                  |
diff --git a/composer.json b/composer.json
index a2bebf0..697320b 100644
--- a/composer.json
+++ b/composer.json
@@ -24,8 +24,8 @@
     "prefer-stable": true,
     "require": {
         "php": ">=8.0",
-        "php-static-analysis/attributes": "^0.1.8 || dev-main",
-        "php-static-analysis/node-visitor": "^0.1.8 || dev-main",
+        "php-static-analysis/attributes": "^0.1.9 || dev-main",
+        "php-static-analysis/node-visitor": "^0.1.9 || dev-main",
         "phpstan/phpstan": "^1.8"
     },
     "require-dev": {
diff --git a/src/Parser/AttributeParser.php b/src/Parser/AttributeParser.php
index 7b49a23..65119e6 100644
--- a/src/Parser/AttributeParser.php
+++ b/src/Parser/AttributeParser.php
@@ -35,7 +35,7 @@ public function parseString(string $sourceCode): array
     private function traverseAst(array $ast): array
     {
         $traverser = new NodeTraverser();
-        $nodeVisitor = new AttributeNodeVisitor();
+        $nodeVisitor = new AttributeNodeVisitor('phpstan');
         $traverser->addVisitor($nodeVisitor);
 
         $ast = $traverser->traverse($ast);
diff --git a/tests/InternalAttributeTest.php b/tests/InternalAttributeTest.php
new file mode 100644
index 0000000..b1158d3
--- /dev/null
+++ b/tests/InternalAttributeTest.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension;
+
+class InternalAttributeTest extends BaseAttributeTestCase
+{
+    public function testClassInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/ClassInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testTraitInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/TraitInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testInterfaceInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/InterfaceInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testMethodInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/MethodInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testFunctionInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/FunctionInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testProperyInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/PropertyInternalAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testInvalidMethodInternalAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Internal/InvalidMethodInternalAttribute.php');
+        $expectedErrors = [
+            'Parameter #1 $namespace of attribute class PhpStaticAnalysis\Attributes\Internal constructor expects string|null, int given.' => 9,
+            'Attribute class PhpStaticAnalysis\Attributes\Internal does not have the parameter target.' => 15,
+            'Attribute class PhpStaticAnalysis\Attributes\Internal is not repeatable but is already present above the method.' => 22,
+        ];
+
+        $this->checkExpectedErrors($errors, $expectedErrors);
+    }
+}
diff --git a/tests/data/Internal/ClassInternalAttribute.php b/tests/data/Internal/ClassInternalAttribute.php
new file mode 100644
index 0000000..6619622
--- /dev/null
+++ b/tests/data/Internal/ClassInternalAttribute.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+#[Internal('newNamespace\test')] // Can only be accessed from the current namespace
+class ClassInternalAttribute
+{
+    #[Internal]
+    public function myFunction(): void
+    {
+    }
+}
+
+namespace newNamespace\test;
+
+class newClass
+{
+    public function newFunction(): void
+    {
+        $class = new \test\PhpStaticAnalysis\PHPStanExtension\data\Internal\ClassInternalAttribute();
+
+        $class->myFunction();
+    }
+}
+
+namespace newNamespace\other;
+
+class otherClass
+{
+    public function otherFunction(): void
+    {
+        $class = new \test\PhpStaticAnalysis\PHPStanExtension\data\Internal\ClassInternalAttribute();
+
+        $class->myFunction();
+    }
+}
diff --git a/tests/data/Internal/FunctionInternalAttribute.php b/tests/data/Internal/FunctionInternalAttribute.php
new file mode 100644
index 0000000..04d8405
--- /dev/null
+++ b/tests/data/Internal/FunctionInternalAttribute.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+#[Internal]
+function returnInternal(): void
+{
+}
diff --git a/tests/data/Internal/InterfaceInternalAttribute.php b/tests/data/Internal/InterfaceInternalAttribute.php
new file mode 100644
index 0000000..cb6e3cc
--- /dev/null
+++ b/tests/data/Internal/InterfaceInternalAttribute.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+#[Internal]
+interface InterfaceInternalAttribute
+{
+}
diff --git a/tests/data/Internal/InvalidMethodInternalAttribute.php b/tests/data/Internal/InvalidMethodInternalAttribute.php
new file mode 100644
index 0000000..8c57080
--- /dev/null
+++ b/tests/data/Internal/InvalidMethodInternalAttribute.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+class InvalidMethodInternalAttribute
+{
+    #[Internal(0)]
+    public function getName(): void
+    {
+    }
+
+    public function getExtraName(
+        #[Internal]
+        string $name
+    ): string {
+        return $name;
+    }
+
+    #[Internal]
+    #[Internal]
+    public function getMoreName(): void
+    {
+    }
+}
diff --git a/tests/data/Internal/MethodInternalAttribute.php b/tests/data/Internal/MethodInternalAttribute.php
new file mode 100644
index 0000000..1ad29e5
--- /dev/null
+++ b/tests/data/Internal/MethodInternalAttribute.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+class MethodInternalAttribute
+{
+    #[Internal]
+    public function returnInternal(): void
+    {
+    }
+
+    /**
+     * @codeCoverageIgnore
+     */
+    #[Internal]
+    public function returnAnotherInternal(): void
+    {
+    }
+
+    /**
+     * @internal
+     */
+    public function returnMoreInternals(): void
+    {
+    }
+}
diff --git a/tests/data/Internal/PropertyInternalAttribute.php b/tests/data/Internal/PropertyInternalAttribute.php
new file mode 100644
index 0000000..52eff2a
--- /dev/null
+++ b/tests/data/Internal/PropertyInternalAttribute.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+class PropertyInternalAttribute
+{
+    #[Internal]
+    public const NAME = 'name';
+
+    #[Internal]
+    public string $name = '';
+}
diff --git a/tests/data/Internal/TraitInternalAttribute.php b/tests/data/Internal/TraitInternalAttribute.php
new file mode 100644
index 0000000..3c13fe9
--- /dev/null
+++ b/tests/data/Internal/TraitInternalAttribute.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Internal;
+
+use PhpStaticAnalysis\Attributes\Internal;
+
+#[Internal]
+trait TraitInternalAttribute
+{
+}