diff --git a/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs b/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
index 7df6086d..466e22ca 100644
--- a/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
+++ b/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
@@ -694,7 +694,7 @@ namespace Newtonsoft.Json.Serialization
             return JsonTypeReflector.ReflectionDelegateFactory.CreateDefaultConstructor<object>(createdType);
         }
 
-#if !NET20
+#if NET35
         [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Portability", "CA1903:UseOnlyApiFromTargetedFramework", MessageId = "System.Runtime.Serialization.DataContractAttribute.#get_IsReference()")]
 #endif
         private void InitializeContract(JsonContract contract)
diff --git a/Src/Newtonsoft.Json/project.json b/Src/Newtonsoft.Json/project.json
index aacedc30..2b461622 100644
--- a/Src/Newtonsoft.Json/project.json
+++ b/Src/Newtonsoft.Json/project.json
@@ -53,7 +53,6 @@
         "System.Collections": "",
         "System.Core": "",
         "System.Diagnostics.Debug": "",
-        "System.Diagnostics.Tools": "",
         "System.Dynamic.Runtime": "",
         "System.Globalization": "",
         "System.IO": "",
@@ -96,7 +95,6 @@
         "System.Collections.Concurrent": "4.0.10",
         "System.ComponentModel.TypeConverter": "4.0.0",
         "System.Diagnostics.Debug": "4.0.10",
-        "System.Diagnostics.Tools": "4.0.0",
         "System.Dynamic.Runtime": "4.0.10",
         "System.Globalization": "4.0.10",
         "System.IO": "4.0.10",