diff --git a/tests/ImageSharp.Tests/Formats/WebP/Serialization/Vp8CostArrayJsonConverter.cs b/tests/ImageSharp.Tests/Formats/WebP/Serialization/Vp8CostArrayJsonConverter.cs
new file mode 100644
index 0000000000..b3cfd03401
--- /dev/null
+++ b/tests/ImageSharp.Tests/Formats/WebP/Serialization/Vp8CostArrayJsonConverter.cs
@@ -0,0 +1,15 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using SixLabors.ImageSharp.Formats.Webp.Lossy;
+
+namespace SixLabors.ImageSharp.Tests.Formats.WebP.Serialization;
+
+internal class Vp8CostArrayJsonConverter : JsonConverter<Vp8CostArray>
+{
+    public override Vp8CostArray Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) => throw new NotImplementedException();
+
+    public override void Write(Utf8JsonWriter writer, Vp8CostArray value, JsonSerializerOptions options) => throw new NotImplementedException();
+}
diff --git a/tests/ImageSharp.Tests/Formats/WebP/Vp8ResidualTests.cs b/tests/ImageSharp.Tests/Formats/WebP/Vp8ResidualTests.cs
index cadf92973c..457f3576fe 100644
--- a/tests/ImageSharp.Tests/Formats/WebP/Vp8ResidualTests.cs
+++ b/tests/ImageSharp.Tests/Formats/WebP/Vp8ResidualTests.cs
@@ -5,7 +5,9 @@ using System.Runtime.Intrinsics.X86;
 using System.Text.Json;
 using SixLabors.ImageSharp.Formats.Webp;
 using SixLabors.ImageSharp.Formats.Webp.Lossy;
+using SixLabors.ImageSharp.Tests.Formats.WebP.Serialization;
 using SixLabors.ImageSharp.Tests.TestUtilities;
+using JsonSerializer = System.Text.Json.JsonSerializer;
 
 namespace SixLabors.ImageSharp.Tests.Formats.Webp;
 
@@ -13,29 +15,30 @@ namespace SixLabors.ImageSharp.Tests.Formats.Webp;
 public class Vp8ResidualTests
 {
     [Fact]
-    public void GetResidualCost_Works()
+    public void Vp8CostArray_Serialization_Works()
     {
-        if (!Sse2.IsSupported)
+        // arrange
+        Vp8CostArray expected = new();
+        for (ushort i = 0; i < expected.Costs.Length; i++)
         {
-            // JsonSerializer without SSE2 does not seem to work, skip test then.
-            return;
+            expected.Costs[i] = i;
         }
 
-        // arrange
-        int ctx0 = 0;
-        int expected = 20911;
-        string jsonString = File.ReadAllText(Path.Combine("TestDataWebp", "Vp8Residual.json"));
-        Vp8Residual residual = JsonSerializer.Deserialize<Vp8Residual>(jsonString);
+        JsonSerializerOptions options = new()
+        {
+            Converters = { new Vp8CostArrayJsonConverter() }
+        };
 
         // act
-        int actual = residual.GetResidualCost(ctx0);
+        string jsonString = JsonSerializer.Serialize(expected);
+        Vp8CostArray actual = JsonSerializer.Deserialize<Vp8CostArray>(jsonString, options);
 
         // assert
-        Assert.Equal(expected, actual);
+        Assert.Equal(expected.Costs, actual.Costs);
     }
 
     [Fact]
-    public void Serialization_Works()
+    public void Vp8Residual_Serialization_Works()
     {
         if (!Sse2.IsSupported)
         {
@@ -101,6 +104,30 @@ public class Vp8ResidualTests
         }
     }
 
+    [Fact]
+    public void GetResidualCost_Works()
+    {
+        if (!Sse2.IsSupported)
+        {
+            // JsonSerializer without SSE2 does not seem to work, skip test then.
+            return;
+        }
+
+        // arrange
+        int ctx0 = 0;
+        int expected = 20911;
+        string jsonString = File.ReadAllText(Path.Combine("TestDataWebp", "Vp8Residual.json"));
+        Vp8Residual residual = JsonSerializer.Deserialize<Vp8Residual>(jsonString);
+
+        // act
+        int actual = residual.GetResidualCost(ctx0);
+
+        // assert
+        Assert.Equal(expected, actual);
+    }
+
+    
+
     private static void CreateRandomProbas(Vp8EncProba probas, Random rand)
     {
         for (int t = 0; t < WebpConstants.NumTypes; ++t)