diff --git a/src/WireMock.Net/Validation/ValidatedNotNullAttribute.cs b/src/WireMock.Net/Validation/ValidatedNotNullAttribute.cs
index 6af21f0d9..5c4f1d053 100644
--- a/src/WireMock.Net/Validation/ValidatedNotNullAttribute.cs
+++ b/src/WireMock.Net/Validation/ValidatedNotNullAttribute.cs
@@ -1,6 +1,6 @@
 using System;
 
-namespace Stef.Validation
+namespace WireMock.Validation
 {
     /// <summary>
     /// To fix 'xxx' is null on at least one execution path. See also https://rules.sonarsource.com/csharp/RSPEC-3900.
@@ -8,4 +8,4 @@ namespace Stef.Validation
     internal class ValidatedNotNullAttribute : Attribute
     {
     }
-}
+}
\ No newline at end of file