diff --git a/Test/UnitTests/BehaviorUtilities.cs b/Test/UnitTests/BehaviorUtilities.cs
index 2bb00d8..3202940 100644
--- a/Test/UnitTests/BehaviorUtilities.cs
+++ b/Test/UnitTests/BehaviorUtilities.cs
@@ -168,8 +168,10 @@ public override void Fail(string message)
         }
         #endregion
 
+#if !NETCOREAPP
         private TraceListener[] storedListeners;
-        private DebugTraceListener debugTraceListener;
+#endif
+        private DebugTraceListener debugTraceListener = new DebugTraceListener();
 
         public List<string> Messages
         {
@@ -205,4 +207,4 @@ public void Dispose()
 
 #endregion
     }
-}
\ No newline at end of file
+}