diff --git a/src/JapaneseCrossword.Core/packages.config b/src/JapaneseCrossword.Core/packages.config
index ba07d01..102f159 100644
--- a/src/JapaneseCrossword.Core/packages.config
+++ b/src/JapaneseCrossword.Core/packages.config
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Newtonsoft.Json" version="12.0.1" targetFramework="net46" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net46" />
 </packages>
\ No newline at end of file