diff --git a/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj b/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
index a0760a87..0d0b6019 100644
--- a/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
+++ b/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
@@ -54,7 +54,7 @@
     <!-- align test project with minimal required version for TaskSeq -->
     <!-- we use 6.0.3 here and not 6.0.2 because TaskResult lib requires it-->
     <PackageReference Update="FSharp.Core" Version="6.0.3" />
-    <PackageReference Include="FsToolkit.ErrorHandling.TaskResult" Version="3.2.0" />
+    <PackageReference Include="FsToolkit.ErrorHandling.TaskResult" Version="4.0.0" />
     <PackageReference Include="FsUnit.xUnit" Version="5.1.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
     <PackageReference Include="xunit" Version="2.4.2" />