diff --git a/src/Testing/src/TestPlatformHelper.cs b/src/Testing/src/TestPlatformHelper.cs
index c72bea38d896..be175324d55a 100644
--- a/src/Testing/src/TestPlatformHelper.cs
+++ b/src/Testing/src/TestPlatformHelper.cs
@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.InternalTesting;
 public static class TestPlatformHelper
 {
     public static bool IsMono =>
-        Type.GetType("Mono.Runtime") != null;
+        Type.GetType("Mono.Runtime") != null || Type.GetType("Mono.RuntimeStructs") != null;
 
     public static bool IsWindows =>
         RuntimeInformation.IsOSPlatform(OSPlatform.Windows);