diff --git a/src/Adapter/MSTest.TestAdapter/MSTestSettings.cs b/src/Adapter/MSTest.TestAdapter/MSTestSettings.cs
index 1be800f802..b773252ee3 100644
--- a/src/Adapter/MSTest.TestAdapter/MSTestSettings.cs
+++ b/src/Adapter/MSTest.TestAdapter/MSTestSettings.cs
@@ -865,11 +865,7 @@ private static void SetParallelSettings(XmlReader reader, MSTestSettings setting
     private static bool TryParseEnum<T>(string value, out T result)
         where T : struct, Enum
         => Enum.TryParse(value, true, out result)
-#if NET6_0_OR_GREATER
-        && Enum.IsDefined(result);
-#else
-        && Enum.IsDefined(typeof(T), result);
-#endif
+        && EnumPolyfill.IsDefined(result);
 
     private static void SetGlobalSettings(
         [StringSyntax(StringSyntaxAttribute.Xml, nameof(runsettingsXml))] string runsettingsXml,