diff --git a/tests/Unit/Mapper/Mappers/JsonToObjectMapperTest.php b/tests/Unit/Mapper/Mappers/JsonToObjectMapperTest.php
index c6c6584..574de5b 100644
--- a/tests/Unit/Mapper/Mappers/JsonToObjectMapperTest.php
+++ b/tests/Unit/Mapper/Mappers/JsonToObjectMapperTest.php
@@ -4,6 +4,7 @@
 
 namespace Tests\Tempest\Unit\Mapper\Mappers;
 
+use Tempest\Mapper\Mappers\JsonToObjectMapper;
 use function Tempest\map;
 use Tests\Tempest\IntegrationTest;
 use Tests\Tempest\Unit\Mapper\Fixtures\ObjectA;
@@ -21,4 +22,18 @@ public function test_json_to_object(): void
         $this->assertSame('a', $object->a);
         $this->assertSame('b', $object->b);
     }
+
+    public function test_invalid_json(): void
+    {
+        $mapper = new JsonToObjectMapper();
+
+        $this->assertFalse($mapper->canMap('invalid', ObjectA::class));
+    }
+
+    public function test_invalid_object(): void
+    {
+        $mapper = new JsonToObjectMapper();
+
+        $this->assertFalse($mapper->canMap('{}', 'unknown'));
+    }
 }