diff --git a/sample/Sink/CustomHttpClient.cs b/sample/Sink/CustomHttpClient.cs
index 4a53b1c..aae671a 100644
--- a/sample/Sink/CustomHttpClient.cs
+++ b/sample/Sink/CustomHttpClient.cs
@@ -1,5 +1,6 @@
 using System.IO;
 using System.Net.Http;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Configuration;
 using Serilog.Sinks.Http;