diff --git a/src/libraries/System.Net.Http/tests/FunctionalTests/DiagnosticsTests.cs b/src/libraries/System.Net.Http/tests/FunctionalTests/DiagnosticsTests.cs
index 4a067b778fb89..8da624c76fd86 100644
--- a/src/libraries/System.Net.Http/tests/FunctionalTests/DiagnosticsTests.cs
+++ b/src/libraries/System.Net.Http/tests/FunctionalTests/DiagnosticsTests.cs
@@ -13,6 +13,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.DotNet.RemoteExecutor;
+using Microsoft.DotNet.XUnitExtensions;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -236,6 +237,12 @@ await RemoteExecutor.Invoke(async (useVersion, testAsync) =>
         [ConditionalFact(typeof(RemoteExecutor), nameof(RemoteExecutor.IsSupported))]
         public async Task SendAsync_ExpectedDiagnosticCancelledLogging()
         {
+            if (UseVersion == HttpVersion30)
+            {
+                // [ActiveIssue("https://github.com/dotnet/runtime/issues/104699")]
+                throw new SkipTestException("SendAsync_ExpectedDiagnosticCancelledLogging is broken on HTTP/3.");
+            }
+
             await RemoteExecutor.Invoke(async (useVersion, testAsync) =>
             {
                 TaskCompletionSource responseLoggedTcs = new(TaskCreationOptions.RunContinuationsAsynchronously);
diff --git a/src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs b/src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs
index ea34d7bf2479d..18d3ee156e785 100644
--- a/src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs
+++ b/src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs
@@ -292,6 +292,14 @@ public SocketsHttpHandler_DiagnosticsTest_Http2(ITestOutputHelper output) : base
         protected override Version UseVersion => HttpVersion.Version20;
     }
 
+    [ConditionalClass(typeof(HttpClientHandlerTestBase), nameof(IsQuicSupported))]
+    [ActiveIssue("https://github.com/dotnet/runtime/issues/103703", typeof(PlatformDetection), nameof(PlatformDetection.IsArmProcess))]
+    public sealed class SocketsHttpHandler_DiagnosticsTest_Http3 : DiagnosticsTest
+    {
+        public SocketsHttpHandler_DiagnosticsTest_Http3(ITestOutputHelper output) : base(output) { }
+        protected override Version UseVersion => HttpVersion.Version30;
+    }
+
     public sealed class SocketsHttpHandler_HttpClient_SelectedSites_Test : HttpClient_SelectedSites_Test
     {
         public SocketsHttpHandler_HttpClient_SelectedSites_Test(ITestOutputHelper output) : base(output) { }