diff --git a/src/TensorFlowNET.Core/Graphs/Graph.cs b/src/TensorFlowNET.Core/Graphs/Graph.cs
index f45fddaf..50d76979 100644
--- a/src/TensorFlowNET.Core/Graphs/Graph.cs
+++ b/src/TensorFlowNET.Core/Graphs/Graph.cs
@@ -17,6 +17,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Collections.Specialized;
 using System.Linq;
 using System.Runtime.InteropServices;
 using static Tensorflow.Binding;