diff --git a/test/Microsoft.NET.Build.Tests/RoslynBuildTaskTests.cs b/test/Microsoft.NET.Build.Tests/RoslynBuildTaskTests.cs
index 7b3055d90d06..84346f5905a6 100644
--- a/test/Microsoft.NET.Build.Tests/RoslynBuildTaskTests.cs
+++ b/test/Microsoft.NET.Build.Tests/RoslynBuildTaskTests.cs
@@ -87,6 +87,36 @@ public void DotNet_ToolsetPackage(bool useSharedCompilation, Language language)
         VerifyCompiler(buildCommand, DotNetExecCompilerFileName(language), CoreTargetFrameworkName, useSharedCompilation, toolsetPackage: true);
     }
 
+    /// <summary>
+    /// SDK side test for <see href="https://github.com/dotnet/roslyn/pull/80993"/>.
+    /// </summary>
+    [FullMSBuildOnlyFact]
+    public void UsingCscManually()
+    {
+        var testInstance = _testAssetsManager.CreateTestDirectory();
+
+        File.WriteAllText(Path.Join(testInstance.Path, "Test.csproj"), $"""
+            <Project Sdk="Microsoft.NET.Sdk">
+                <PropertyGroup>
+                    <TargetFramework>{ToolsetInfo.CurrentTargetFramework}</TargetFramework>
+                </PropertyGroup>
+                <Target Name="CustomTarget">
+                    <Csc Sources="File.cs" />
+                </Target>
+            </Project>
+            """);
+
+        File.WriteAllText(Path.Join(testInstance.Path, "File.cs"), """
+            using System.Linq;
+            System.Console.WriteLine();
+            """);
+
+        new MSBuildCommand(Log, "CustomTarget", testInstance.Path)
+            .WithWorkingDirectory(testInstance.Path)
+            .Execute()
+            .Should().Pass();
+    }
+
     private TestAsset CreateProject(bool useSharedCompilation, Language language, Action<TestProject>? configure = null, [CallerMemberName] string callingMethod = "")
     {
         var (projExtension, sourceName, sourceText) = language switch