diff --git a/Scripts/Editor/CompressionTests.cs b/Scripts/Editor/CompressionTests.cs
index 53bdfeb..1eebdb2 100644
--- a/Scripts/Editor/CompressionTests.cs
+++ b/Scripts/Editor/CompressionTests.cs
@@ -1,4 +1,5 @@
-using NUnit.Framework;
+#if UNITY_5_3_OR_NEWER
+using NUnit.Framework;
 using System;
 using System.IO;
 using System.Linq;
@@ -215,3 +216,4 @@ public class CompressionTests  {
 
     }
 }
+#endif