diff --git a/tests/ImageSharp.Tests/Formats/WebP/WebpDecoderTests.cs b/tests/ImageSharp.Tests/Formats/WebP/WebpDecoderTests.cs
index 5384a02c96..0bf4b5dcf2 100644
--- a/tests/ImageSharp.Tests/Formats/WebP/WebpDecoderTests.cs
+++ b/tests/ImageSharp.Tests/Formats/WebP/WebpDecoderTests.cs
@@ -14,6 +14,7 @@ using static SixLabors.ImageSharp.Tests.TestImages.WebP;
 // ReSharper disable InconsistentNaming
 namespace SixLabors.ImageSharp.Tests.Formats.Webp
 {
+    [Collection("RunSerial")]
     [Trait("Format", "Webp")]
     public class WebpDecoderTests
     {
diff --git a/tests/ImageSharp.Tests/Formats/WebP/WebpEncoderTests.cs b/tests/ImageSharp.Tests/Formats/WebP/WebpEncoderTests.cs
index 44ae674f3b..8de790b982 100644
--- a/tests/ImageSharp.Tests/Formats/WebP/WebpEncoderTests.cs
+++ b/tests/ImageSharp.Tests/Formats/WebP/WebpEncoderTests.cs
@@ -10,6 +10,7 @@ using static SixLabors.ImageSharp.Tests.TestImages.WebP;
 
 namespace SixLabors.ImageSharp.Tests.Formats.Webp
 {
+    [Collection("RunSerial")]
     [Trait("Format", "Webp")]
     public class WebpEncoderTests
     {