diff --git a/Src/Newtonsoft.Json/Serialization/JsonTypeReflector.cs b/Src/Newtonsoft.Json/Serialization/JsonTypeReflector.cs
index 7ec74474..f546978e 100644
--- a/Src/Newtonsoft.Json/Serialization/JsonTypeReflector.cs
+++ b/Src/Newtonsoft.Json/Serialization/JsonTypeReflector.cs
@@ -403,7 +403,9 @@ namespace Newtonsoft.Json.Serialization
       {
         if (_fullyTrusted == null)
         {
-#if !(NET20 || NET35 || SILVERLIGHT || NETFX_CORE)
+#if (NETFX_CORE || SILVERLIGHT)
+          _fullyTrusted = false;
+#elif !(NET20 || NET35)
           AppDomain appDomain = AppDomain.CurrentDomain;
 
           _fullyTrusted = appDomain.IsHomogenous && appDomain.IsFullyTrusted;