diff --git a/composer.json b/composer.json
index 0db07f05c8d..56e83bbe24b 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
         "php": "^8.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "^11.0",
+        "phpunit/phpunit": "^9.6",
         "symfony/yaml": "^7.0",
         "ibexa/connector-gemini": "5.0.x-dev",
         "ibexa/automated-translation": "5.0.x-dev",
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index e084420e57c..becfd51dcca 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/11.0/phpunit.xsd"
+    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.6/phpunit.xsd"
     bootstrap="tests/bootstrap.php"
     colors="true"
     failOnWarning="true"
diff --git a/tests/InlineSamples/InlinePhpPipelineTest.php b/tests/InlineSamples/InlinePhpPipelineTest.php
index e02405ca658..14a8530e92c 100644
--- a/tests/InlineSamples/InlinePhpPipelineTest.php
+++ b/tests/InlineSamples/InlinePhpPipelineTest.php
@@ -8,7 +8,6 @@
 
 namespace Ibexa\Tests\Documentation\InlineSamples;
 
-use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -209,8 +208,9 @@ public function testMultiLineChangePreservesStructure(): void
 
     /**
      * @param array<string, string> $fixerReplacements
+     *
+     * @dataProvider provideIdempotencyCases
      */
-    #[DataProvider('provideIdempotencyCases')]
     public function testPipelineIsIdempotent(string $md, array $fixerReplacements): void
     {
         // First pass (may or may not change the Markdown).
diff --git a/tests/InlineSamples/InlinePhpSyncerTest.php b/tests/InlineSamples/InlinePhpSyncerTest.php
index 7013707d61e..8456bc5b813 100644
--- a/tests/InlineSamples/InlinePhpSyncerTest.php
+++ b/tests/InlineSamples/InlinePhpSyncerTest.php
@@ -8,7 +8,6 @@
 
 namespace Ibexa\Tests\Documentation\InlineSamples;
 
-use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -311,8 +310,9 @@ public function testSyncHandlesIndentedBlockWithPhpTagAndBlankLine(): void
 
     /**
      * @param array<string, string> $replacements Simulated cs-fixer changes: old => new.
+     *
+     * @dataProvider provideRoundtripCases
      */
-    #[DataProvider('provideRoundtripCases')]
     public function testRoundtripAppliesChangesAndIsIdempotent(
         string $md,
         array $replacements,
diff --git a/tests/InlineSamples/InlinePhpWriterTest.php b/tests/InlineSamples/InlinePhpWriterTest.php
index 9b0d8439fb6..2988e1fb33a 100644
--- a/tests/InlineSamples/InlinePhpWriterTest.php
+++ b/tests/InlineSamples/InlinePhpWriterTest.php
@@ -8,7 +8,6 @@
 
 namespace Ibexa\Tests\Documentation\InlineSamples;
 
-use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -141,8 +140,9 @@ public function testBodyAfterPhpTagContainsNamespace(): void
     /**
      * @param string $body         Input body (from MarkdownExtractor)
      * @param string $expectedBody Expected body section after the blank separator
+     *
+     * @dataProvider provideExactContent
      */
-    #[DataProvider('provideExactContent')]
     public function testExactFileContent(string $sourcePath, int $line, string $body, string $expectedBody): void
     {
         $expected = sprintf(InlinePhpWriter::FILE_TEMPLATE, $sourcePath, $line, $expectedBody);
diff --git a/tests/InlineSamples/MarkdownExtractorTest.php b/tests/InlineSamples/MarkdownExtractorTest.php
index 7cf6e312aaf..4f8808b2100 100644
--- a/tests/InlineSamples/MarkdownExtractorTest.php
+++ b/tests/InlineSamples/MarkdownExtractorTest.php
@@ -8,7 +8,6 @@
 
 namespace Ibexa\Tests\Documentation\InlineSamples;
 
-use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 final class MarkdownExtractorTest extends TestCase
@@ -185,8 +184,9 @@ public function testSkipsOnlyMatchingBlocksWhenMixed(): void
 
     /**
      * @param array<array{body: string, line: int}> $expected
+     *
+     * @dataProvider provideMultilineBlocks
      */
-    #[DataProvider('provideMultilineBlocks')]
     public function testExtractsMultilineBody(string $content, array $expected): void
     {
         $blocks = iterator_to_array($this->extractor->extract($content));
diff --git a/tests/Markdown/MarkdownYamlExtractorTest.php b/tests/Markdown/MarkdownYamlExtractorTest.php
index 0575ae51df7..2cdfa4ce6f2 100644
--- a/tests/Markdown/MarkdownYamlExtractorTest.php
+++ b/tests/Markdown/MarkdownYamlExtractorTest.php
@@ -8,7 +8,6 @@
 
 namespace Ibexa\Tests\Documentation\Markdown;
 
-use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 final class MarkdownYamlExtractorTest extends TestCase
@@ -185,8 +184,9 @@ public function testSkipsOnlyMatchingBlocksWhenMixed(): void
 
     /**
      * @param array<array{body: string, line: int}> $expected
+     *
+     * @dataProvider provideMultilineBlocks
      */
-    #[DataProvider('provideMultilineBlocks')]
     public function testExtractsMultilineBody(string $content, array $expected): void
     {
         $blocks = iterator_to_array($this->extractor->extract($content));
diff --git a/tests/Yaml/YamlTest.php b/tests/Yaml/YamlTest.php
index 112ba951fc3..2df011170e1 100644
--- a/tests/Yaml/YamlTest.php
+++ b/tests/Yaml/YamlTest.php
@@ -10,20 +10,22 @@
 
 use Ibexa\Tests\Documentation\ConfigurationProvider;
 use Ibexa\Tests\Documentation\ValidationBaseline;
-use PHPUnit\Framework\Attributes\DataProvider;
-use PHPUnit\Framework\Attributes\Group;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\Definition\Processor;
 use Symfony\Component\Yaml\Exception\ParseException;
 use Symfony\Component\Yaml\Yaml;
 
-#[Group('yaml')]
+/**
+ * @group yaml
+ */
 final class YamlTest extends TestCase
 {
     private const string REPO_ROOT = __DIR__ . '/../../';
     private const string BASELINE_FILE = __DIR__ . '/../yaml-validation-baseline.yaml';
 
-    #[DataProvider('provideYamlSources')]
+    /**
+     * @dataProvider provideYamlSources
+     */
     public function testYamlIsSyntacticallyValid(string $filePath, int $line, string $body, string $bodyHash): void
     {
         $filePath = self::relativePath($filePath);
@@ -54,8 +56,9 @@ public function testYamlIsSyntacticallyValid(string $filePath, int $line, string
 
     /**
      * @param int $line Starting line of the config block (0 for standalone YAML files).
+     *
+     * @dataProvider provideBundleConfigs
      */
-    #[DataProvider('provideBundleConfigs')]
     public function testBundleConfigurationIsValid(
         string $extensionName,
         mixed $config,