diff --git a/test/Microsoft.NET.Build.Tests/GivenThatWeWantMSBuildToRespectCustomCulture.cs b/test/Microsoft.NET.Build.Tests/GivenThatWeWantMSBuildToRespectCustomCulture.cs
index e81667d635bc..1bebbd693c4f 100644
--- a/test/Microsoft.NET.Build.Tests/GivenThatWeWantMSBuildToRespectCustomCulture.cs
+++ b/test/Microsoft.NET.Build.Tests/GivenThatWeWantMSBuildToRespectCustomCulture.cs
@@ -27,9 +27,32 @@ public void SupportRespectAlreadyAssignedItemCulture_ByDefault_ForDotnet9(string
             new FileInfo(Path.Combine(outputDirectory, "test-2", "MSBuildCultureResourceGeneration.resources.dll")).Should().Exist();
         }
 
-        [Theory]
+        [CoreMSBuildOnlyTheory]
+        [InlineData("net7.0")]
+        [InlineData("net6.0")]
+        public void SupportRespectAlreadyAssignedItemCulture_IsNotSupported_BuildShouldWarn(string targetFramework)
+        {
+            var testAsset = _testAssetsManager
+                .CopyTestAsset("MSBuildCultureResourceGeneration", identifier: targetFramework)
+                .WithSource()
+                .WithTargetFramework(targetFramework);
+
+            var buildCommand = new BuildCommand(testAsset);
+            // Custom culture is allowed, but if set explicitly and overwritten - a warning is issued.
+            buildCommand.Execute().Should().Pass().And
+                // warning MSB3002: Explicitly set culture "test-1" for item "Resources.test-1.resx" was overwritten with inferred culture "", because 'RespectAlreadyAssignedItemCulture' property was not set.
+                .HaveStdOutContaining("warning MSB3002:");
+        }
+
+        [FullMSBuildOnlyTheory]
         [InlineData("net7.0")]
         [InlineData("net6.0")]
+        // Is this Failing? Is full FW MSBuild already on 17.13? Then remove this test and remove `[CoreMSBuildOnlyTheory]` attribute on the test above
+        //
+        // Until MSBuild 17.13 is merged into FullFW MSBuild in sdk tests - the test will fail, as
+        //  proper recognition of custom cultures in RAR is not supported and hence the build will fail during copy:
+        //
+        // Microsoft.Common.CurrentVersion.targets(4959,5): error MSB3030: Could not copy the file "obj\Debug\net7.0\test-1\MSBuildCultureResourceGeneration.resources.dll" because it was not found.
         public void SupportRespectAlreadyAssignedItemCulture_IsNotSupported_BuildShouldFail(string targetFramework)
         {
             var testAsset = _testAssetsManager