Callable with wider parameter type is supertype of callable with narrower parameter type

src/Type/CallableTypeHelper.php

@@ -74,7 +74,7 @@ public static function isParametersAcceptorSuperTypeOf(
 			if ($treatMixedAsAny) {
 				$isSuperType = $theirParameter->getType()->acceptsWithReason($ourParameterType, true);
 			} else {
-				$isSuperType = new AcceptsResult($theirParameter->getType()->isSuperTypeOf($ourParameterType), []);
+				$isSuperType = new AcceptsResult($ourParameterType->isSuperTypeOf($theirParameter->getType()), []);
 			}
 
 			if ($isSuperType->maybe()) {

tests/PHPStan/Analyser/nsrt/bug-11285.php

@@ -0,0 +1,58 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug11285;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @template T
+ * @template U
+ */
+class Templated
+{
+
+	/**
+	 * @param callable(T|U): void $callback
+	 */
+	public function compare(callable $callback): void {
+
+	}
+}
+
+class ClassA {}
+class ClassB {}
+
+
+class Test
+{
+	/**
+	 * @param Templated<ClassA, ClassB>|Templated<ClassA, ClassA> $t
+	 */
+	public function broken(
+		Templated $t,
+	): void
+	{
+		$t->compare(
+			static function (ClassA|ClassB $crate): void {
+				assertType('Bug11285\\ClassA|Bug11285\\ClassB', $crate);
+			}
+		);
+	}
+
+	/**
+	 * @param Templated<ClassA, ClassB> $t
+	 */
+	public function working(
+		Templated $t,
+	): void
+	{
+		$t->compare(
+			static function (ClassA|ClassB $crate): void {
+				assertType('Bug11285\\ClassA|Bug11285\\ClassB', $crate);
+			}
+		);
+	}
+
+}

tests/PHPStan/Type/CallableTypeTest.php

@@ -43,12 +43,12 @@ public function dataIsSuperTypeOf(): array
 			[
 				new CallableType([new NativeParameterReflection('foo', false, new MixedType(), PassedByReference::createNo(), false, null)], new MixedType(), false),
 				new CallableType([new NativeParameterReflection('foo', false, new IntegerType(), PassedByReference::createNo(), false, null)], new MixedType(), false),
-				TrinaryLogic::createMaybe(),
+				TrinaryLogic::createYes(),
 			],
 			[
 				new CallableType([new NativeParameterReflection('foo', false, new IntegerType(), PassedByReference::createNo(), false, null)], new MixedType(), false),
 				new CallableType([new NativeParameterReflection('foo', false, new MixedType(), PassedByReference::createNo(), false, null)], new MixedType(), false),
-				TrinaryLogic::createYes(),
+				TrinaryLogic::createMaybe(),
 			],
 			[
 				new CallableType([

tests/PHPStan/Type/TypeCombinatorTest.php

@@ -16,6 +16,7 @@
 use ObjectShapesAcceptance\ClassWithFooIntProperty;
 use PHPStan\Fixture\FinalClass;
 use PHPStan\Reflection\Callables\SimpleImpurePoint;
+use PHPStan\Reflection\Php\DummyParameter;
 use PHPStan\Testing\PHPStanTestCase;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryLiteralStringType;
@@ -2568,6 +2569,36 @@ public function dataUnion(): iterable
 			ClosureType::class,
 			'Closure(): mixed',
 		];
+		yield [
+			[
+				new CallableType([
+					new DummyParameter('callback', new ObjectType('stdClass'), false, null, false, null),
+				], new VoidType(), false),
+				new CallableType([
+					new DummyParameter('callback', new UnionType([
+						new ObjectType('stdClass'),
+						new ObjectType('Exception'),
+					]), false, null, false, null),
+				], new VoidType(), false),
+			],
+			CallableType::class,
+			'callable(Exception|stdClass): void',
+		];
+		yield [
+			[
+				new CallableType([
+					new DummyParameter('callback', new ObjectType('stdClass'), false, null, false, null),
+				], new VoidType(), false),
+				new CallableType([
+					new DummyParameter('callback', new UnionType([
+						new IntegerType(),
+						new ObjectType('Exception'),
+					]), false, null, false, null),
+				], new VoidType(), false),
+			],
+			UnionType::class,
+			'(callable(Exception|int): void)|(callable(stdClass): void)',
+		];
 	}
 
 	/**