diff --git a/src/Rules/PHPUnit/AssertRuleHelper.php b/src/Rules/PHPUnit/AssertRuleHelper.php
index 5971fc0..5fb958d 100644
--- a/src/Rules/PHPUnit/AssertRuleHelper.php
+++ b/src/Rules/PHPUnit/AssertRuleHelper.php
@@ -50,6 +50,7 @@ public static function isMethodOrStaticCallOnAssert(Node $node, Scope $scope): b
 	public static function hasNamedOrUnpackedArguments(CallLike $call): bool
 	{
 		foreach ($call->getArgs() as $arg) {
+			// PHPUnit does not support named arguments for most of its APIs, e.g. assert*.
 			if ($arg->name !== null || $arg->unpack) {
 				return true;
 			}
diff --git a/src/Rules/PHPUnit/AssertSameWithCountRule.php b/src/Rules/PHPUnit/AssertSameWithCountRule.php
index 2a5a765..196037c 100644
--- a/src/Rules/PHPUnit/AssertSameWithCountRule.php
+++ b/src/Rules/PHPUnit/AssertSameWithCountRule.php
@@ -5,6 +5,7 @@
 use Countable;
 use PhpParser\Node;
 use PhpParser\Node\Expr\CallLike;
+use PhpParser\NodeAbstract;
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
@@ -50,6 +51,21 @@ public function processNode(Node $node, Scope $scope): array
 			return [
 				RuleErrorBuilder::message('You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, count($variable)).')
 					->identifier('phpunit.assertCount')
+					->fixNode($node, static function (CallLike $node) use ($scope) {
+						if (AssertRuleHelper::hasNamedOrUnpackedArguments($node)) {
+							return $node;
+						}
+
+						$newArgs = self::rewriteArgs($node->args, $scope);
+						if ($newArgs === null) {
+							return $node;
+						}
+
+						$node->name = new Node\Identifier('assertCount');
+						$node->args = $newArgs;
+
+						return $node;
+					})
 					->build(),
 			];
 		}
@@ -58,6 +74,21 @@ public function processNode(Node $node, Scope $scope): array
 			return [
 				RuleErrorBuilder::message('You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, $variable->count()).')
 					->identifier('phpunit.assertCount')
+					->fixNode($node, static function (CallLike $node) use ($scope) {
+						if (AssertRuleHelper::hasNamedOrUnpackedArguments($node)) {
+							return $node;
+						}
+
+						$newArgs = self::rewriteArgs($node->args, $scope);
+						if ($newArgs === null) {
+							return $node;
+						}
+
+						$node->name = new Node\Identifier('assertCount');
+						$node->args = $newArgs;
+
+						return $node;
+					})
 					->build(),
 			];
 		}
@@ -109,4 +140,48 @@ private static function isNormalCount(Node\Expr\FuncCall $countFuncCall, Type $c
 		return $isNormalCount;
 	}
 
+	/**
+	 * @template T of NodeAbstract
+	 * @param array<T> $args
+	 * @return list<T|Node\Arg>|null
+	 */
+	private static function rewriteArgs(array $args, Scope $scope): ?array
+	{
+		$newArgs = [];
+		foreach ($args as $i => $arg) {
+			if (!$arg instanceof Node\Arg) {
+				$newArgs[] = $arg;
+				continue;
+			}
+
+			if ($i !== 1 || !$arg->value instanceof CallLike) {
+				$newArgs[] = $arg;
+				continue;
+			}
+
+			$callLike = $arg->value;
+
+			// for now skip more complex cases
+			if (AssertRuleHelper::hasNamedOrUnpackedArguments($callLike)) {
+				return null;
+			}
+
+			if (self::isCountFunctionCall($callLike, $scope)) {
+				if (count($callLike->getArgs()) !== 1) {
+					return null;
+				}
+
+				$newArgs[] = new Node\Arg($callLike->getArgs()[0]->value);
+				continue;
+			} elseif (self::isCountableMethodCall($callLike, $scope)) {
+				$newArgs[] = new Node\Arg($callLike->var);
+				continue;
+			}
+
+			return null;
+		}
+
+		return $newArgs;
+	}
+
 }
diff --git a/tests/Rules/PHPUnit/AssertSameWithCountRuleTest.php b/tests/Rules/PHPUnit/AssertSameWithCountRuleTest.php
index dfb940c..188a9cd 100644
--- a/tests/Rules/PHPUnit/AssertSameWithCountRuleTest.php
+++ b/tests/Rules/PHPUnit/AssertSameWithCountRuleTest.php
@@ -4,6 +4,7 @@
 
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
+use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<AssertSameWithCountRule>
@@ -42,6 +43,39 @@ public function testRule(): void
 		]);
 	}
 
+	public function testFix(): void
+	{
+		$this->fix(__DIR__ . '/data/assert-same-count-fixable.php', __DIR__ . '/data/assert-same-count-fixable.php.fixed');
+		// we don't expect any fixes for named arguments
+		$this->fix(__DIR__ . '/data/assert-same-count-named-arguments.php', __DIR__ . '/data/assert-same-count-named-arguments.php');
+	}
+
+	public function testNamedArguments(): void
+	{
+		if (PHP_VERSION_ID < 80000) {
+			self::markTestSkipped('Named arguments require PHP 8.0.');
+		}
+
+		$this->analyse([__DIR__ . '/data/assert-same-count-named-arguments.php'], [
+			[
+				'You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, count($variable)).',
+				12,
+			],
+			[
+				'You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, count($variable)).',
+				13,
+			],
+			[
+				'You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, count($variable)).',
+				15,
+			],
+			[
+				'You should use assertCount($expectedCount, $variable) instead of assertSame($expectedCount, count($variable)).',
+				17,
+			],
+		]);
+	}
+
 	/**
 	 * @return string[]
 	 */
diff --git a/tests/Rules/PHPUnit/data/assert-same-count-fixable.php b/tests/Rules/PHPUnit/data/assert-same-count-fixable.php
new file mode 100644
index 0000000..85e4163
--- /dev/null
+++ b/tests/Rules/PHPUnit/data/assert-same-count-fixable.php
@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace ExampleTestCaseFix;
+
+use const COUNT_RECURSIVE;
+
+class AssertSameWithCountTestCase extends \PHPUnit\Framework\TestCase
+{
+
+	public function testAssertSameWithCount()
+	{
+		$this->assertSame(5, count([1, 2, 3]));
+	}
+
+	public function testAssertSameWithCountCallsInOtherArguments($expected, $actual, \Countable $countable)
+	{
+		$this->assertSame(count($expected), count($actual));
+		$this->assertSame(count($expected), count($actual), getMessage());
+		$this->assertSame(count($expected), $countable->count(), getMessage());
+	}
+
+	public function testAssertSameWithCountUnpackedArguments(array $args)
+	{
+		$this->assertSame(5, count(...$args));
+	}
+
+	public function testAssertSameWithCountRecursive($x)
+	{
+		$this->assertSame(5, count([1, 2, 3, $x], COUNT_RECURSIVE));
+	}
+
+	public function testAssertSameWithCountMethodForCountableVariableIsNotOK()
+	{
+		$bar = new \ExampleTestCaseFix\Bar ();
+
+		$this->assertSame(5, $bar->count());
+	}
+
+	public function testAssertSameWithCountMethodForCountablePropertyFetchIsNotOK()
+	{
+		$foo = new \stdClass();
+		$foo->bar = new Bar ();
+
+		$this->assertSame(5, $foo->bar->count());
+	}
+
+}
+
+class Bar implements \Countable {
+	public function count(): int
+	{
+		return 1;
+	}
+}
diff --git a/tests/Rules/PHPUnit/data/assert-same-count-fixable.php.fixed b/tests/Rules/PHPUnit/data/assert-same-count-fixable.php.fixed
new file mode 100644
index 0000000..8a2dc42
--- /dev/null
+++ b/tests/Rules/PHPUnit/data/assert-same-count-fixable.php.fixed
@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace ExampleTestCaseFix;
+
+use const COUNT_RECURSIVE;
+
+class AssertSameWithCountTestCase extends \PHPUnit\Framework\TestCase
+{
+
+	public function testAssertSameWithCount()
+	{
+		$this->assertCount(5, [1, 2, 3]);
+	}
+
+	public function testAssertSameWithCountCallsInOtherArguments($expected, $actual, \Countable $countable)
+	{
+		$this->assertCount(count($expected), $actual);
+		$this->assertCount(count($expected), $actual, getMessage());
+		$this->assertCount(count($expected), $countable, getMessage());
+	}
+
+	public function testAssertSameWithCountUnpackedArguments(array $args)
+	{
+		$this->assertSame(5, count(...$args));
+	}
+
+	public function testAssertSameWithCountRecursive($x)
+	{
+		$this->assertSame(5, count([1, 2, 3, $x], COUNT_RECURSIVE));
+	}
+
+	public function testAssertSameWithCountMethodForCountableVariableIsNotOK()
+	{
+		$bar = new \ExampleTestCaseFix\Bar ();
+
+		$this->assertCount(5, $bar);
+	}
+
+	public function testAssertSameWithCountMethodForCountablePropertyFetchIsNotOK()
+	{
+		$foo = new \stdClass();
+		$foo->bar = new Bar ();
+
+		$this->assertCount(5, $foo->bar);
+	}
+
+}
+
+class Bar implements \Countable {
+	public function count(): int
+	{
+		return 1;
+	}
+}
diff --git a/tests/Rules/PHPUnit/data/assert-same-count-named-arguments.php b/tests/Rules/PHPUnit/data/assert-same-count-named-arguments.php
new file mode 100644
index 0000000..7f0402e
--- /dev/null
+++ b/tests/Rules/PHPUnit/data/assert-same-count-named-arguments.php
@@ -0,0 +1,30 @@
+<?php // lint >= 8.0
+
+namespace ExampleTestCaseFixNamedArguments;
+
+use function count;
+
+class AssertSameWithCountTestCase extends \PHPUnit\Framework\TestCase
+{
+
+	public function skipNamedArguments(Bar $bar): void
+	{
+		$this->assertSame(expected: 5, actual: count([1, 2, 3]), message: 'message');
+		$this->assertSame(message: 'message', actual: count(value: [1, 2, 3]), expected: 5);
+		self::assertSame(actual: $bar->count(), expected: 5);
+		$this->assertSame(5, actual: count([1, 2, 3]), message: 'message');
+
+		$this->assertSame(5, count(value: [1, 2, 3]), 'message');
+	}
+
+}
+
+class Bar implements \Countable
+{
+
+	public function count(): int
+	{
+		return 1;
+	}
+
+}