diff --git a/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj b/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
old mode 100755
new mode 100644
index 1aa314f4ae..84de3f9f04
--- a/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
+++ b/src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj
@@ -14,7 +14,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="NUnit" Version="3.10.1" />
     <PackageReference Include="NUnitLite" Version="3.10.1" />
     <PackageReference Include="OpenCover" Version="4.6.519" />