diff --git a/src/EventSourcingTests/removing_protected_information.cs b/src/EventSourcingTests/removing_protected_information.cs
index 8aaca8f880..cc03146e6f 100644
--- a/src/EventSourcingTests/removing_protected_information.cs
+++ b/src/EventSourcingTests/removing_protected_information.cs
@@ -53,8 +53,8 @@ public void match_exactly_on_event_type_when_record()
 
         theEvents.TryMask(@event).ShouldBeTrue();
 
-        started.FirstName.ShouldBe("John");
-        started.LastName.ShouldBe("****");
+        @event.Data.FirstName.ShouldBe("John");
+        @event.Data.LastName.ShouldBe("****");
     }
 
     [Fact]
diff --git a/src/Marten/Events/EventGraph.Masking.cs b/src/Marten/Events/EventGraph.Masking.cs
index b252cbcda6..69612e191b 100644
--- a/src/Marten/Events/EventGraph.Masking.cs
+++ b/src/Marten/Events/EventGraph.Masking.cs
@@ -83,9 +83,9 @@ public FuncMasker(Func<T,T> masking)
 
     public bool TryMask(IEvent @event)
     {
-        if (@event is IEvent<T> e)
+        if (@event is Event<T> e)
         {
-            e.WithData(_masking(e.Data));
+            e.Data = _masking(e.Data);
             return true;
         }
 
diff --git a/src/Marten/Events/IEventStoreOptions.cs b/src/Marten/Events/IEventStoreOptions.cs
index 08a0cb5bd2..277671cdf7 100644
--- a/src/Marten/Events/IEventStoreOptions.cs
+++ b/src/Marten/Events/IEventStoreOptions.cs
@@ -352,9 +352,18 @@ public IEventStoreOptions Upcast<TOldEvent, TEvent>(
         /// for an event type "T" or series of event types that can be cast
         /// to "T"
         /// </summary>
-        /// <param name="action"></param>
+        /// <param name="action">Action to mask the current object</param>
         /// <typeparam name="T"></typeparam>
         void AddMaskingRuleForProtectedInformation<T>(Action<T> action);
+
+        /// <summary>
+        /// Register a policy for how to remove or mask protected information
+        /// for an event type "T" or series of event types that can be cast
+        /// to "T"
+        /// </summary>
+        /// <param name="func">Function to replace the event with a masked event</param>
+        /// <typeparam name="T"></typeparam>
+        void AddMaskingRuleForProtectedInformation<T>(Func<T, T> func);
     }
 }