1 files changed, 1 insertions, 1 deletions

diff --git a/src/WixToolset.Core/Mutator.cs b/src/WixToolset.Core/Mutator.cs
index 7f1af13a..cee17736 100644
--- a/src/WixToolset.Core/Mutator.cs
+++ b/src/WixToolset.Core/Mutator.cs
@@ -10,7 +10,7 @@ namespace WixToolset.Core
     /// <summary>
     /// The WiX Toolset mutator.
     /// </summary>
-    public sealed class Mutator
+    public class Mutator
     {
         private SortedList extensions;
         private string extensionArgument;