diff --git a/phpstan.neon b/phpstan.neon
index f5da971..8a310a5 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -4,3 +4,4 @@ parameters:
     checkMissingCallableSignature: true
     paths:
         - src
+        - tests
diff --git a/src/lib/PhpCsFixer/Rule/MultilineParametersFixer.php b/src/lib/PhpCsFixer/Rule/MultilineParametersFixer.php
new file mode 100644
index 0000000..cbe75ba
--- /dev/null
+++ b/src/lib/PhpCsFixer/Rule/MultilineParametersFixer.php
@@ -0,0 +1,182 @@
+<?php
+
+/**
+ * @copyright Copyright (C) Ibexa AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace Ibexa\CodeStyle\PhpCsFixer\Rule;
+
+use PhpCsFixer\AbstractFixer;
+use PhpCsFixer\FixerDefinition\CodeSample;
+use PhpCsFixer\FixerDefinition\FixerDefinition;
+use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
+use PhpCsFixer\Tokenizer\Token;
+use PhpCsFixer\Tokenizer\Tokens;
+
+final class MultilineParametersFixer extends AbstractFixer
+{
+    public function getDefinition(): FixerDefinitionInterface
+    {
+        return new FixerDefinition(
+            'Methods and functions with 2+ parameters must use multiline format',
+            [
+                new CodeSample(
+                    '<?php function foo(string $a, int $b): void {}'
+                ),
+            ]
+        );
+    }
+
+    public function isCandidate(Tokens $tokens): bool
+    {
+        return $tokens->isTokenKindFound(T_FUNCTION);
+    }
+
+    protected function applyFix(
+        \SplFileInfo $file,
+        Tokens $tokens
+    ): void {
+        for ($index = $tokens->count() - 1; $index >= 0; --$index) {
+            if (!$tokens[$index]->isGivenKind(T_FUNCTION)) {
+                continue;
+            }
+
+            $openParentIndex = $tokens->getNextTokenOfKind($index, ['(']);
+            if ($openParentIndex === null) {
+                continue;
+            }
+
+            $closeParentIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_PARENTHESIS_BRACE, $openParentIndex);
+
+            // Count commas to determine parameter count
+            $paramCount = $this->countParameters($tokens, $openParentIndex, $closeParentIndex);
+
+            // Only process if 2+ parameters
+            if ($paramCount < 2) {
+                continue;
+            }
+
+            // Check if already multiline
+            if ($this->isMultiline($tokens, $openParentIndex, $closeParentIndex)) {
+                continue;
+            }
+
+            // Apply multiline formatting
+            $this->makeMultiline($tokens, $openParentIndex, $closeParentIndex);
+        }
+    }
+
+    private function countParameters(
+        Tokens $tokens,
+        int $start,
+        int $end
+    ): int {
+        $count = 0;
+        $depth = 0;
+
+        for ($i = $start + 1; $i < $end; ++$i) {
+            if ($tokens[$i]->equals('(') || $tokens[$i]->equals('[')) {
+                ++$depth;
+            } elseif ($tokens[$i]->equals(')') || $tokens[$i]->equals(']')) {
+                --$depth;
+            } elseif ($depth === 0 && $tokens[$i]->equals(',')) {
+                ++$count;
+            }
+        }
+
+        // If we found any commas, param count is commas + 1
+        // If no commas but there's content, it's 1 param
+        if ($count > 0) {
+            return $count + 1;
+        }
+
+        // Check if there's any non-whitespace content
+        for ($i = $start + 1; $i < $end; ++$i) {
+            if (!$tokens[$i]->isWhitespace()) {
+                return 1;
+            }
+        }
+
+        return 0;
+    }
+
+    private function isMultiline(
+        Tokens $tokens,
+        int $start,
+        int $end
+    ): bool {
+        for ($i = $start; $i <= $end; ++$i) {
+            if ($tokens[$i]->isGivenKind(T_WHITESPACE) && str_contains($tokens[$i]->getContent(), "\n")) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private function makeMultiline(
+        Tokens $tokens,
+        int $openParentIndex,
+        int $closeParentIndex
+    ): void {
+        $indent = $this->detectIndent($tokens, $openParentIndex);
+        $lineIndent = str_repeat(' ', 4); // 4 spaces for parameters
+
+        // Add newline after opening parenthesis
+        $tokens->insertAt($openParentIndex + 1, new Token([T_WHITESPACE, "\n" . $indent . $lineIndent]));
+        ++$closeParentIndex;
+
+        // Find all commas and add newlines after them
+        $depth = 0;
+        for ($i = $openParentIndex + 1; $i < $closeParentIndex; ++$i) {
+            if ($tokens[$i]->equals('(') || $tokens[$i]->equals('[')) {
+                ++$depth;
+            } elseif ($tokens[$i]->equals(')') || $tokens[$i]->equals(']')) {
+                --$depth;
+            } elseif ($depth === 0 && $tokens[$i]->equals(',')) {
+                // Remove any whitespace after comma
+                $nextIndex = $i + 1;
+                while ($nextIndex < $closeParentIndex && $tokens[$nextIndex]->isWhitespace()) {
+                    $tokens->clearAt($nextIndex);
+                    ++$nextIndex;
+                }
+
+                // Insert newline with proper indentation
+                $tokens->insertAt($i + 1, new Token([T_WHITESPACE, "\n" . $indent . $lineIndent]));
+                $closeParentIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_PARENTHESIS_BRACE, $openParentIndex);
+            }
+        }
+
+        // Add newline before closing parenthesis
+        $tokens->insertAt($closeParentIndex, new Token([T_WHITESPACE, "\n" . $indent]));
+
+        // Handle the opening brace
+        $nextNonWhitespace = $tokens->getNextNonWhitespace($closeParentIndex);
+        if ($nextNonWhitespace !== null && $tokens[$nextNonWhitespace]->equals('{')) {
+            $tokens->ensureWhitespaceAtIndex($nextNonWhitespace - 1, 1, ' ');
+        }
+    }
+
+    private function detectIndent(
+        Tokens $tokens,
+        int $index
+    ): string {
+        // Look backwards to find the indentation of the current line
+        for ($i = $index - 1; $i >= 0; --$i) {
+            if ($tokens[$i]->isGivenKind(T_WHITESPACE) && str_contains($tokens[$i]->getContent(), "\n")) {
+                $lines = explode("\n", $tokens[$i]->getContent());
+
+                return end($lines);
+            }
+        }
+
+        return '';
+    }
+
+    public function getName(): string
+    {
+        return 'Ibexa/multiline_parameters';
+    }
+}
diff --git a/src/lib/PhpCsFixer/Sets/AbstractIbexaRuleSet.php b/src/lib/PhpCsFixer/Sets/AbstractIbexaRuleSet.php
index 4ccf3f6..079b8fb 100644
--- a/src/lib/PhpCsFixer/Sets/AbstractIbexaRuleSet.php
+++ b/src/lib/PhpCsFixer/Sets/AbstractIbexaRuleSet.php
@@ -9,6 +9,7 @@
 namespace Ibexa\CodeStyle\PhpCsFixer\Sets;
 
 use AdamWojs\PhpCsFixerPhpdocForceFQCN\Fixer\Phpdoc\ForceFQCNFixer;
+use Ibexa\CodeStyle\PhpCsFixer\Rule\MultilineParametersFixer;
 use PhpCsFixer\Config;
 
 abstract class AbstractIbexaRuleSet implements RuleSetInterface
@@ -26,6 +27,7 @@ public function getRules(): array
         return [
             '@PSR12' => false,
             'AdamWojs/phpdoc_force_fqcn_fixer' => true,
+            'Ibexa/multiline_parameters' => true,
             'array_syntax' => [
                 'syntax' => 'short',
             ],
@@ -204,7 +206,7 @@ public function getRules(): array
     public function buildConfig(): Config
     {
         $config = new Config();
-        $config->registerCustomFixers([new ForceFQCNFixer()]);
+        $config->registerCustomFixers([new ForceFQCNFixer(), new MultilineParametersFixer()]);
 
         $config->setRules(array_merge(
             $config->getRules(),
diff --git a/tests/lib/PhpCsFixer/InternalConfigFactoryTest.php b/tests/lib/PhpCsFixer/InternalConfigFactoryTest.php
index 71ef115..e85f80c 100644
--- a/tests/lib/PhpCsFixer/InternalConfigFactoryTest.php
+++ b/tests/lib/PhpCsFixer/InternalConfigFactoryTest.php
@@ -37,14 +37,22 @@ protected function setUp(): void
 
     /**
      * @dataProvider provideRuleSetTestCases
+     *
+     * @param array{name: string, version: string, pretty_version?: string} $package
+     * @param class-string $expectedRuleSetClass
      */
-    public function testVersionBasedRuleSetSelection(array $package, string $expectedRuleSetClass): void
-    {
+    public function testVersionBasedRuleSetSelection(
+        array $package,
+        string $expectedRuleSetClass
+    ): void {
         $ruleSet = $this->createRuleSetFromPackage->invoke($this->factory, $package);
 
         self::assertInstanceOf($expectedRuleSetClass, $ruleSet);
     }
 
+    /**
+     * @return array<string, array{0: array{name: string, version: string, pretty_version?: string}, 1: class-string}>
+     */
     public function provideRuleSetTestCases(): array
     {
         return [
diff --git a/tests/lib/PhpCsFixer/Rule/MultilineParametersFixerTest.php b/tests/lib/PhpCsFixer/Rule/MultilineParametersFixerTest.php
new file mode 100644
index 0000000..61f536c
--- /dev/null
+++ b/tests/lib/PhpCsFixer/Rule/MultilineParametersFixerTest.php
@@ -0,0 +1,116 @@
+<?php
+
+/**
+ * @copyright Copyright (C) Ibexa AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace Ibexa\Tests\CodeStyle\PhpCsFixer\Rule;
+
+use Ibexa\CodeStyle\PhpCsFixer\Rule\MultilineParametersFixer;
+use PhpCsFixer\Tokenizer\Tokens;
+use PHPUnit\Framework\TestCase;
+use SplFileInfo;
+
+final class MultilineParametersFixerTest extends TestCase
+{
+    private MultilineParametersFixer $fixer;
+
+    protected function setUp(): void
+    {
+        $this->fixer = new MultilineParametersFixer();
+    }
+
+    /**
+     * @dataProvider provideFixCases
+     */
+    public function testFix(
+        string $input,
+        string $expected
+    ): void {
+        $tokens = Tokens::fromCode($input);
+        $this->fixer->fix(new SplFileInfo(__FILE__), $tokens);
+
+        self::assertSame($expected, $tokens->generateCode());
+    }
+
+    /**
+     * @return iterable<string, array{0: string, 1: string}>
+     */
+    public static function provideFixCases(): iterable
+    {
+        yield 'single parameter should not be modified' => [
+            '<?php
+function bar(array $package): void {
+}',
+            '<?php
+function bar(array $package): void {
+}',
+        ];
+
+        yield 'single parameter with type hints should not be modified' => [
+            '<?php
+function bar(?string $package = null): void {
+}',
+            '<?php
+function bar(?string $package = null): void {
+}',
+        ];
+
+        yield 'multiple parameters should be split' => [
+            '<?php
+function foo(array $package, string $expectedRuleSetClass): void {
+}',
+            '<?php
+function foo(
+    array $package,
+    string $expectedRuleSetClass
+): void {
+}',
+        ];
+
+        yield 'multiple parameters with type hints should be split' => [
+            '<?php
+function test(?string $foo = null, int $bar = 42): string {
+}',
+            '<?php
+function test(
+    ?string $foo = null,
+    int $bar = 42
+): string {
+}',
+        ];
+
+        yield 'constructor with properties should be split' => [
+            '<?php
+class Test {
+    public function __construct(string $foo, int $bar) {
+    }
+}',
+            '<?php
+class Test {
+    public function __construct(
+        string $foo,
+        int $bar
+    ) {
+    }
+}',
+        ];
+
+        yield 'already multiline should not be modified' => [
+            '<?php
+function test(
+    string $foo,
+    int $bar
+): void {
+}',
+            '<?php
+function test(
+    string $foo,
+    int $bar
+): void {
+}',
+        ];
+    }
+}
diff --git a/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/local_rules.php b/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/local_rules.php
index cc469e9..53a74b5 100644
--- a/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/local_rules.php
+++ b/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/local_rules.php
@@ -195,4 +195,5 @@
     'visibility_required' => true,
     'whitespace_after_comma_in_array' => true,
     'yoda_style' => false,
+    'Ibexa/multiline_parameters' => true,
 ];
diff --git a/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/php_cs_fixer_rules.php b/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/php_cs_fixer_rules.php
index ca860a8..700bc04 100644
--- a/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/php_cs_fixer_rules.php
+++ b/tests/lib/PhpCsFixer/Sets/expected_rules/4_6_rule_set/php_cs_fixer_rules.php
@@ -179,4 +179,5 @@
     'no_trailing_comma_in_singleline_array' => true,
     'no_unneeded_curly_braces' => true,
     'single_blank_line_before_namespace' => true,
+    'Ibexa/multiline_parameters' => true,
 ];
diff --git a/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/local_rules.php b/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/local_rules.php
index 37e51fb..f0685d5 100644
--- a/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/local_rules.php
+++ b/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/local_rules.php
@@ -218,4 +218,5 @@
     'visibility_required' => true,
     'whitespace_after_comma_in_array' => true,
     'yoda_style' => false,
+    'Ibexa/multiline_parameters' => true,
 ];
diff --git a/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/php_cs_fixer_rules.php b/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/php_cs_fixer_rules.php
index a50d32f..e4b9f51 100644
--- a/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/php_cs_fixer_rules.php
+++ b/tests/lib/PhpCsFixer/Sets/expected_rules/5_0_rule_set/php_cs_fixer_rules.php
@@ -204,4 +204,5 @@
     'types_spaces' => [
         'space' => 'single',
     ],
+    'Ibexa/multiline_parameters' => true,
 ];