diff --git a/sandbox/PertNetFramework/packages.config b/sandbox/PertNetFramework/packages.config
index 57581f217..a6152455f 100644
--- a/sandbox/PertNetFramework/packages.config
+++ b/sandbox/PertNetFramework/packages.config
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="MsgPack.Cli" version="0.9.0-beta2" targetFramework="net461" />
-  <package id="Newtonsoft.Json" version="10.0.1-beta1" targetFramework="net461" />
+  <package id="Newtonsoft.Json" version="13.0.2" targetFramework="net461" />
   <package id="protobuf-net" version="2.1.0" targetFramework="net461" />
   <package id="System.Threading.Tasks.Extensions" version="4.3.0" targetFramework="net461" />
   <package id="System.ValueTuple" version="4.3.0" targetFramework="net461" />