diff --git a/SDL3-CS.Tests/TestUtf8String.cs b/SDL3-CS.Tests/TestUtf8String.cs
index 2c4ec5c..be97d99 100644
--- a/SDL3-CS.Tests/TestUtf8String.cs
+++ b/SDL3-CS.Tests/TestUtf8String.cs
@@ -14,6 +14,7 @@ namespace SDL3.Tests
         {
             checkNull(null);
             checkNull(default);
+            checkNull(new Utf8String()); // don't do this in actual code
         }
 
         [TestCase(null, -1)]