diff --git a/Chapter2_WPF_Controls/Exercise13.Tests/packages.config b/Chapter2_WPF_Controls/Exercise13.Tests/packages.config
index d72bc30..65a0e31 100644
--- a/Chapter2_WPF_Controls/Exercise13.Tests/packages.config
+++ b/Chapter2_WPF_Controls/Exercise13.Tests/packages.config
@@ -3,7 +3,7 @@
   <package id="Guts.Client" version="3.0.0" targetFramework="net472" />
   <package id="Guts.Client.Shared" version="3.0.0" targetFramework="net472" />
   <package id="Microsoft.AspNet.WebApi.Client" version="5.2.7" targetFramework="net472" />
-  <package id="Newtonsoft.Json" version="12.0.3" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net472" />
   <package id="NUnit" version="3.12.0" targetFramework="net472" />
   <package id="NUnit3TestAdapter" version="3.16.1" targetFramework="net472" developmentDependency="true" />
   <package id="WindowsBase" version="4.6.1055.0" targetFramework="net472" />