@@ -11,8 +11,8 @@
 use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
-use PHPStan\Type\TypeWithClassName;
 use function array_key_exists;
+use function count;
 
 class MockObjectTypeNodeResolverExtension implements TypeNodeResolverExtension, TypeNodeResolverAwareExtension
 {
@@ -44,11 +44,12 @@ public function resolve(TypeNode $typeNode, NameScope $nameScope): ?Type
 
 $types = $this->typeNodeResolver->resolveMultiple($typeNode->types, $nameScope);
 foreach ($types as $type) {
-if (!$type instanceof TypeWithClassName) {
+$classNames = $type->getObjectClassNames();
+if (count($classNames) !== 1) {
 continue;
 }
 
-if (array_key_exists($type->getClassName(), $mockClassNames)) {
+if (array_key_exists($classNames[0], $mockClassNames)) {
 $resultType = TypeCombinator::intersect(...$types);
 if ($resultType instanceof NeverType) {
 continue;

@@ -6,7 +6,6 @@
 use PhpParser\Node\Expr\MethodCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
-use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\ObjectType;
@@ -44,53 +43,56 @@ public function processNode(Node $node, Scope $scope): array
 }
 
 $argType = $scope->getType($node->getArgs()[0]->value);
-if (!($argType instanceof ConstantStringType)) {
+if (count($argType->getConstantStrings()) === 0) {
 return [];
 }
 
-$method = $argType->getValue();
-$type = $scope->getType($node->var);
-
-if (
-$type instanceof IntersectionType
-&& (
-in_array(MockObject::class, $type->getReferencedClasses(), true)
-|| in_array(Stub::class, $type->getReferencedClasses(), true)
-)
-&& !$type->hasMethod($method)->yes()
-) {
-$mockClass = array_filter($type->getReferencedClasses(), static function (string $class): bool {
-return $class !== MockObject::class && $class !== Stub::class;
-});
-
-return [
-sprintf(
+$errors = [];
+foreach ($argType->getConstantStrings() as $constantString) {
+$method = $constantString->getValue();
+$type = $scope->getType($node->var);
+
+if (
+$type instanceof IntersectionType
+&& (
+in_array(MockObject::class, $type->getObjectClassNames(), true)
+|| in_array(Stub::class, $type->getObjectClassNames(), true)
+)
+&& !$type->hasMethod($method)->yes()
+) {
+$mockClass = array_filter($type->getObjectClassNames(), static function (string $class): bool {
+return $class !== MockObject::class && $class !== Stub::class;
+});
+
+$errors[] = sprintf(
 'Trying to mock an undefined method %s() on class %s.',
 $method,
 implode('&', $mockClass)
-),
-];
-}
+);
+}
+
+if (
+!($type instanceof GenericObjectType)
+|| $type->getClassName() !== InvocationMocker::class
+|| count($type->getTypes()) <= 0
+) {
+continue;
+}
 
-if (
-$type instanceof GenericObjectType
-&& $type->getClassName() === InvocationMocker::class
-&& count($type->getTypes()) > 0
-) {
 $mockClass = $type->getTypes()[0];
 
-if ($mockClass instanceof ObjectType && !$mockClass->hasMethod($method)->yes()) {
-return [
-sprintf(
-'Trying to mock an undefined method %s() on class %s.',
-$method,
-$mockClass->getClassName()
-),
-];
+if (!($mockClass instanceof ObjectType) || $mockClass->hasMethod($method)->yes()) {
+continue;
 }
+
+$errors[] = sprintf(
+'Trying to mock an undefined method %s() on class %s.',
+$method,
+$mockClass->getClassName()
+);
 }
 
-return [];
+return $errors;
 }
 
 }

@@ -10,7 +10,6 @@
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeWithClassName;
 use PHPUnit\Framework\MockObject\Builder\InvocationMocker;
 use PHPUnit\Framework\MockObject\MockObject;
 use function array_filter;
@@ -38,7 +37,12 @@ public function getTypeFromMethodCall(MethodReflection $methodReflection, Method
 }
 
 $mockClasses = array_values(array_filter($type->getTypes(), static function (Type $type): bool {
-return !$type instanceof TypeWithClassName || $type->getClassName() !== MockObject::class;
+$classNames = $type->getObjectClassNames();
+if (count($classNames) !== 1) {
+return true;
+}
+
+return $classNames[0] !== MockObject::class;
 }));
 
 if (count($mockClasses) !== 1) {