diff --git a/tests/Models/NullCommentListTest.php b/tests/Models/NullCommentListTest.php
index 6181dd2..da44eb3 100755
--- a/tests/Models/NullCommentListTest.php
+++ b/tests/Models/NullCommentListTest.php
@@ -47,6 +47,6 @@ final class NullCommentListTest extends \PHPUnit\Framework\TestCase
     public function testJsonSerialize() : void
     {
         $null = new NullCommentList(2);
-        self::assertEquals(['id' => 2], $null);
+        self::assertEquals(['id' => 2], $null->jsonSerialize());
     }
 }
diff --git a/tests/Models/NullCommentTest.php b/tests/Models/NullCommentTest.php
index eb038d4..79271e3 100755
--- a/tests/Models/NullCommentTest.php
+++ b/tests/Models/NullCommentTest.php
@@ -47,6 +47,6 @@ final class NullCommentTest extends \PHPUnit\Framework\TestCase
     public function testJsonSerialize() : void
     {
         $null = new NullComment(2);
-        self::assertEquals(['id' => 2], $null);
+        self::assertEquals(['id' => 2], $null->jsonSerialize());
     }
 }
diff --git a/tests/Models/NullCommentVoteTest.php b/tests/Models/NullCommentVoteTest.php
index 83b34f5..1cd66b3 100755
--- a/tests/Models/NullCommentVoteTest.php
+++ b/tests/Models/NullCommentVoteTest.php
@@ -47,6 +47,6 @@ final class NullCommentVoteTest extends \PHPUnit\Framework\TestCase
     public function testJsonSerialize() : void
     {
         $null = new NullCommentVote(2);
-        self::assertEquals(['id' => 2], $null);
+        self::assertEquals(['id' => 2], $null->jsonSerialize());
     }
 }