diff --git a/Polyalphabetic/Polyalphabetic.Tests/Polyalphabetic.Tests.csproj b/Polyalphabetic/Polyalphabetic.Tests/Polyalphabetic.Tests.csproj
index 4d98da7..0418f3f 100644
--- a/Polyalphabetic/Polyalphabetic.Tests/Polyalphabetic.Tests.csproj
+++ b/Polyalphabetic/Polyalphabetic.Tests/Polyalphabetic.Tests.csproj
@@ -10,7 +10,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
     <PackageReference Include="MSTest.TestAdapter" Version="2.1.2" />
     <PackageReference Include="MSTest.TestFramework" Version="2.1.2" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.2" />
   </ItemGroup>
 
   <ItemGroup>