diff --git a/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php b/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
index da1defc264..fc909c4369 100644
--- a/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
+++ b/tests/PHPStan/Rules/Classes/InstantiationRuleTest.php
@@ -384,4 +384,14 @@ public function testEnumInstantiation(): void
 		]);
 	}
 
+	public function testBug6370(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-6370.php'], [
+			[
+				'Parameter #1 $something of class Bug6370\A constructor expects string, int given.',
+				45,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Classes/data/bug-6370.php b/tests/PHPStan/Rules/Classes/data/bug-6370.php
new file mode 100644
index 0000000000..5744316ed3
--- /dev/null
+++ b/tests/PHPStan/Rules/Classes/data/bug-6370.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Bug6370;
+
+interface I
+{
+}
+class A implements I
+{
+	public function __construct(string $something)
+	{
+		// one class needs a constructor to reproduce the issue
+		unset($something);
+	}
+}
+class B implements I
+{
+}
+
+class Foo
+{
+
+	function test(string $className): I
+	{
+		if (!in_array($className, [B::class, A::class], true)) {
+			throw new \Exception();
+		}
+		switch($className) {
+			case A::class:
+				return new $className('something');
+			case B::class:
+				return new $className();
+			default:
+				throw new \Exception();
+		}
+	}
+
+	function test2(string $className): I
+	{
+		if (!in_array($className, [B::class, A::class], true)) {
+			throw new \Exception();
+		}
+		switch($className) {
+			case A::class:
+				return new $className(1);
+			case B::class:
+				return new $className();
+			default:
+				throw new \Exception();
+		}
+	}
+
+}
diff --git a/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php b/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php
index 78a7e794cb..52169ba2a7 100644
--- a/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php
+++ b/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php
@@ -930,4 +930,15 @@ public function testFirstClassCallables(): void
 		$this->analyse([__DIR__ . '/data/first-class-callables.php'], []);
 	}
 
+	public function testBug4413(): void
+	{
+		require_once __DIR__ . '/data/bug-4413.php';
+		$this->analyse([__DIR__ . '/data/bug-4413.php'], [
+			[
+				'Parameter #1 $date of function Bug4413\takesDate expects class-string<DateTime>, string given.',
+				18,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Functions/data/bug-4413.php b/tests/PHPStan/Rules/Functions/data/bug-4413.php
new file mode 100644
index 0000000000..3c8b1ffda7
--- /dev/null
+++ b/tests/PHPStan/Rules/Functions/data/bug-4413.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Bug4413;
+
+use DateTime;
+
+/**
+ * @param class-string<DateTime> $date
+ */
+function takesDate(string $date): void {}
+
+function input(string $in): void {
+	switch ($in) {
+		case DateTime::class :
+			takesDate($in);
+			break;
+		case \stdClass::class :
+			takesDate($in);
+			break;
+	}
+}