diff --git a/utils/phpstan-extensions/config/phpstan-extensions.neon b/utils/phpstan-extensions/config/phpstan-extensions.neon
index 7e58451a05e..d95b298dbd4 100644
--- a/utils/phpstan-extensions/config/phpstan-extensions.neon
+++ b/utils/phpstan-extensions/config/phpstan-extensions.neon
@@ -23,6 +23,10 @@ services:
          class: Rector\PHPStanExtensions\Rule\RectorRuleAndValueObjectHaveSameStartsRule
          tags: [phpstan.rules.rule]
 
+    -
+         class: Rector\PHPStanExtensions\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule
+         tags: [phpstan.rules.rule]
+
     - Rector\PHPStanExtensions\Utils\PHPStanValueResolver
 
     # $node->getAttribute($1) => Type|null by $1
diff --git a/utils/phpstan-extensions/src/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule.php b/utils/phpstan-extensions/src/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule.php
new file mode 100644
index 00000000000..d8154f0340a
--- /dev/null
+++ b/utils/phpstan-extensions/src/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPStanExtensions\Rule;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\New_;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\Scalar\String_;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use Rector\Core\RectorDefinition\CodeSample;
+
+/**
+ * @see \Rector\PHPStanExtensions\Tests\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule\CheckCodeSampleBeforeAfterAlwaysDifferentRuleTest
+ */
+final class CheckCodeSampleBeforeAfterAlwaysDifferentRule implements Rule
+{
+    /**
+     * @var string
+     */
+    public const ERROR_MESSAGE = 'Code sample before and after must be different';
+
+    public function getNodeType(): string
+    {
+        return New_::class;
+    }
+
+    /**
+     * @param New_ $node
+     * @return string[]
+     */
+    public function processNode(Node $node, Scope $scope): array
+    {
+        $class = $node->class;
+        if (! $class instanceof FullyQualified) {
+            return [];
+        }
+
+        $className = $class->toString();
+        if ($className !== CodeSample::class) {
+            return [];
+        }
+
+        $args = $node->args;
+        /** @var String_ $firstParameter */
+        $firstParameter = $args[0]->value;
+        /** @var String_ $secondParameter */
+        $secondParameter = $args[1]->value;
+
+        if ($firstParameter->value !== $secondParameter->value) {
+            return [];
+        }
+
+        return [self::ERROR_MESSAGE];
+    }
+}
diff --git a/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/CheckCodeSampleBeforeAfterAlwaysDifferentRuleTest.php b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/CheckCodeSampleBeforeAfterAlwaysDifferentRuleTest.php
new file mode 100644
index 00000000000..f054d7f1735
--- /dev/null
+++ b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/CheckCodeSampleBeforeAfterAlwaysDifferentRuleTest.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPStanExtensions\Tests\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule;
+
+use Iterator;
+use PHPStan\Rules\Rule;
+use Rector\PHPStanExtensions\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule;
+use Symplify\PHPStanExtensions\Testing\AbstractServiceAwareRuleTestCase;
+
+final class CheckCodeSampleBeforeAfterAlwaysDifferentRuleTest extends AbstractServiceAwareRuleTestCase
+{
+    /**
+     * @dataProvider provideData()
+     * @param array<string|string[]|int[]> $expectedErrorsWithLines
+     */
+    public function testRule(string $filePath, array $expectedErrorsWithLines): void
+    {
+        $this->analyse([$filePath], $expectedErrorsWithLines);
+    }
+
+    public function provideData(): Iterator
+    {
+        yield [__DIR__ . '/Fixture/BeforeAfterDifferent.php', []];
+        yield [
+            __DIR__ . '/Fixture/BeforeAfterSame.php',
+            [[CheckCodeSampleBeforeAfterAlwaysDifferentRule::ERROR_MESSAGE, 9]],
+        ];
+    }
+
+    protected function getRule(): Rule
+    {
+        return $this->getRuleFromConfig(
+            CheckCodeSampleBeforeAfterAlwaysDifferentRule::class,
+            __DIR__ . '/../../../config/phpstan-extensions.neon'
+        );
+    }
+}
diff --git a/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterDifferent.php b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterDifferent.php
new file mode 100644
index 00000000000..f19967e5a0a
--- /dev/null
+++ b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterDifferent.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPStanExtensions\Tests\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule\Fixture;
+
+use Rector\Core\RectorDefinition\CodeSample;
+
+new CodeSample('A', 'B');
\ No newline at end of file
diff --git a/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterSame.php b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterSame.php
new file mode 100644
index 00000000000..cc9c269b65f
--- /dev/null
+++ b/utils/phpstan-extensions/tests/Rule/CheckCodeSampleBeforeAfterAlwaysDifferentRule/Fixture/BeforeAfterSame.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPStanExtensions\Tests\Rule\CheckCodeSampleBeforeAfterAlwaysDifferentRule\Fixture;
+
+use Rector\Core\RectorDefinition\CodeSample;
+
+new CodeSample('A', 'A');
\ No newline at end of file