diff --git a/src/MyCSharp.HttpUserAgentParser/HttpUserAgentStatics.cs b/src/MyCSharp.HttpUserAgentParser/HttpUserAgentStatics.cs
index 0ab8f21..842e4ff 100644
--- a/src/MyCSharp.HttpUserAgentParser/HttpUserAgentStatics.cs
+++ b/src/MyCSharp.HttpUserAgentParser/HttpUserAgentStatics.cs
@@ -1,5 +1,7 @@
 // Copyright © myCSharp.de - all rights reserved
 
+using System.Text.RegularExpressions;
+
 namespace MyCSharp.HttpUserAgentParser;
 
 /// <summary>