diff --git a/src/libraries/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.csproj b/src/libraries/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.csproj
index 5173bc185a697..4248550ccc036 100644
--- a/src/libraries/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.csproj
+++ b/src/libraries/System.Net.WebSockets.Client/tests/System.Net.WebSockets.Client.Tests.csproj
@@ -17,7 +17,7 @@
 
     <!-- This WASM test is problematic and slow right now. This sets the xharness timeout but there is also override in sendtohelix-browser.targets -->
     <WasmXHarnessTestsTimeout>01:15:00</WasmXHarnessTestsTimeout>
-    <WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads>
+    <!-- WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads-->
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/System.Runtime/tests/System.Buffers.Tests/System.Buffers.Tests.csproj b/src/libraries/System.Runtime/tests/System.Buffers.Tests/System.Buffers.Tests.csproj
index 66ae6833a50eb..2e77905aff861 100644
--- a/src/libraries/System.Runtime/tests/System.Buffers.Tests/System.Buffers.Tests.csproj
+++ b/src/libraries/System.Runtime/tests/System.Buffers.Tests/System.Buffers.Tests.csproj
@@ -6,7 +6,7 @@
     <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <PropertyGroup Condition="'$(TargetOS)' == 'browser'">
-    <WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads>
+    <!--WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads-->
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="ArrayPool\ArrayPoolTest.cs" />
diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
index 61bea23cac820..65f1a9095680d 100644
--- a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
+++ b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj
@@ -21,7 +21,7 @@
     <XunitShowProgress>true</XunitShowProgress>
     <!-- This WASM test is problematic and slow right now. This sets the xharness timeout but there is also override in sendtohelix-browser.targets -->
     <WasmXHarnessTestsTimeout>01:15:00</WasmXHarnessTestsTimeout>
-    <WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads>
+    <!--WasmXHarnessMaxParallelThreads>1</WasmXHarnessMaxParallelThreads-->
   </PropertyGroup>
   <ItemGroup Condition="'$(ContinuousIntegrationBuild)' == 'true'">
     <HighAotMemoryUsageAssembly Include="System.Text.Json.Tests.dll" />