diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Drivers/AuditTrailSettingsPartDriver.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Drivers/AuditTrailSettingsPartDriver.cs
index da3fa20c1..97e21bc3e 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Drivers/AuditTrailSettingsPartDriver.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Drivers/AuditTrailSettingsPartDriver.cs
@@ -27,22 +27,26 @@ namespace Orchard.AuditTrail.Drivers {
             return ContentShape("Parts_AuditTrailSettings_Edit", () => {
                 var descriptors = _auditTrailManager.DescribeCategories();
                 var eventSettings = part.EventSettings.ToList();
+                var categoriesQuery =
+                    from categoryDescriptor in descriptors
+                    let eventsQuery =
+                        from eventDescriptor in categoryDescriptor.Events
+                        let eventSetting = eventSettings.FirstOrDefault(x => x.EventName == eventDescriptor.Event)
+                        select new AuditTrailEventSettingsViewModel {
+                            Event = eventDescriptor.Event,
+                            Name = eventDescriptor.Name,
+                            Description = eventDescriptor.Description,
+                            IsEnabled = eventDescriptor.IsMandatory || (eventSetting != null ? eventSetting.IsEnabled : eventDescriptor.IsEnabledByDefault),
+                            IsMandatory = eventDescriptor.IsMandatory
+                        }
+                    select new AuditTrailCategorySettingsViewModel {
+                        Category = categoryDescriptor.Category,
+                        Name = categoryDescriptor.Name,
+                        Events = eventsQuery.ToArray()
+                    };
+
                 var viewModel = new AuditTrailSettingsViewModel {
-                    Categories = (from categoryDescriptor in descriptors
-                        select new AuditTrailCategorySettingsViewModel {
-                            Category = categoryDescriptor.Category,
-                            Name = categoryDescriptor.Name,
-                            Events = 
-                                (from eventDescriptor in categoryDescriptor.Events
-                                let eventSetting = eventSettings.FirstOrDefault(x => x.EventName == eventDescriptor.Event)
-                                select new AuditTrailEventSettingsViewModel {
-                                    Event = eventDescriptor.Event,
-                                    Name = eventDescriptor.Name,
-                                    Description = eventDescriptor.Description,
-                                    IsEnabled = eventDescriptor.IsMandatory || (eventSetting != null ? eventSetting.IsEnabled : eventDescriptor.IsEnabledByDefault),
-                                    IsMandatory = eventDescriptor.IsMandatory
-                                }).ToList()
-                        }).ToList()
+                    Categories = categoriesQuery.ToArray() 
                 };
 
                 if (updater != null) {
@@ -55,6 +59,7 @@ namespace Orchard.AuditTrail.Drivers {
                                 eventSettings.Add(eventSetting);
                             }
 
+                            // TODO: Security hole! IsMandatory could be spoofed in the request!
                             eventSetting.IsEnabled = eventSettingViewModel.IsEnabled || eventSettingViewModel.IsMandatory;
                         }
                         part.EventSettings = eventSettings;
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeHelper.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeExtensions.cs
similarity index 92%
rename from src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeHelper.cs
rename to src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeExtensions.cs
index 0b9e0a349..0289ca343 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeHelper.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/DateTimeExtensions.cs
@@ -1,7 +1,7 @@
 using System;
 
 namespace Orchard.AuditTrail.Helpers {
-    public static class DateTimeHelper {
+    public static class DateTimeExtensions {
         public static DateTime? Earliest(this DateTime? value) {
             if (value == null)
                 return null;
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataHelper.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataExtensions.cs
similarity index 89%
rename from src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataHelper.cs
rename to src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataExtensions.cs
index 664af226a..27c66302b 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataHelper.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventDataExtensions.cs
@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 
 namespace Orchard.AuditTrail.Helpers {
-    public static class EventDataHelper {
+    public static class EventDataExtensions {
         public static T Get<T>(this IDictionary<string, object> eventData, string key) {
             if (eventData == null || !eventData.ContainsKey(key))
                 return default(T);
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameHelper.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameExtensions.cs
similarity index 90%
rename from src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameHelper.cs
rename to src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameExtensions.cs
index 64702e7ad..5302a8fa3 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameHelper.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/EventNameExtensions.cs
@@ -2,7 +2,7 @@
 using Orchard.AuditTrail.Services;
 
 namespace Orchard.AuditTrail.Helpers {
-    internal static class EventNameHelper {
+    internal static class EventNameExtensions {
         public static string GetFullyQualifiedEventName<T>(string eventName) where T : IAuditTrailEventProvider {
             return GetFullyQualifiedEventName(typeof(T), eventName);
         }
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersHelper.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersExtensions.cs
similarity index 86%
rename from src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersHelper.cs
rename to src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersExtensions.cs
index 04c7912dc..6dd2e1067 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersHelper.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/FiltersExtensions.cs
@@ -1,7 +1,7 @@
 using Orchard.AuditTrail.Services.Models;
 
 namespace Orchard.AuditTrail.Helpers {
-    public static class FiltersHelper {
+    public static class FiltersExtensions {
         public static string Get(this Filters filters, string key) {
             if (!filters.ContainsKey(key))
                 return null;
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringConversionHelper.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringExtensions.cs
similarity index 86%
rename from src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringConversionHelper.cs
rename to src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringExtensions.cs
index f3f2b40db..224c17986 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringConversionHelper.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Helpers/StringExtensions.cs
@@ -1,7 +1,7 @@
 using System;
 
 namespace Orchard.AuditTrail.Helpers {
-    public static class StringConversionHelper {
+    public static class StringExtensions {
         public static int? ToInt32(this string value) {
             if (String.IsNullOrWhiteSpace(value))
                 return null;
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Orchard.AuditTrail.csproj b/src/Orchard.Web/Modules/Orchard.AuditTrail/Orchard.AuditTrail.csproj
index baee17a45..3ec3e3a6b 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Orchard.AuditTrail.csproj
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Orchard.AuditTrail.csproj
@@ -161,6 +161,14 @@
       <Project>{fe5c5947-d2d5-42c5-992a-13d672946135}</Project>
       <Name>Orchard.ImportExport</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Orchard.Roles\Orchard.Roles.csproj">
+      <Project>{d10ad48f-407d-4db5-a328-173ec7cb010f}</Project>
+      <Name>Orchard.Roles</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\Orchard.Users\Orchard.Users.csproj">
+      <Project>{79aed36e-abd0-4747-93d3-8722b042454b}</Project>
+      <Name>Orchard.Users</Name>
+    </ProjectReference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AdminMenu.cs" />
@@ -169,9 +177,9 @@
     <Compile Include="Drivers\AuditTrailTrimmingSettingsPartDriver.cs" />
     <Compile Include="Drivers\AuditTrailSettingsPartDriver.cs" />
     <Compile Include="Handlers\AuditTrailTrimmingSettingsPartHandler.cs" />
-    <Compile Include="Helpers\FiltersHelper.cs" />
-    <Compile Include="Helpers\DateTimeHelper.cs" />
-    <Compile Include="Helpers\StringConversionHelper.cs" />
+    <Compile Include="Helpers\FiltersExtensions.cs" />
+    <Compile Include="Helpers\DateTimeExtensions.cs" />
+    <Compile Include="Helpers\StringExtensions.cs" />
     <Compile Include="ImportExport\AuditTrailExportStep.cs" />
     <Compile Include="ImportExport\AuditTrailExportHandler.cs" />
     <Compile Include="ImportExport\AuditTrailImportHandler.cs" />
@@ -206,19 +214,17 @@
     <Compile Include="Providers\ContentDefinition\ContentPartAuditTrailEventProvider.cs" />
     <Compile Include="Providers\ContentDefinition\ContentTypeAuditTrailEventProvider.cs" />
     <Compile Include="Providers\Content\AuditTrailEventHandler.cs" />
-    <Compile Include="Helpers\EventDataHelper.cs" />
+    <Compile Include="Helpers\EventDataExtensions.cs" />
     <Compile Include="Services\Models\AuditTrailFilterParameters.cs" />
-    <Compile Include="Providers\Roles\IRoleEventHandler.cs" />
     <Compile Include="Providers\Roles\RoleEventHandler.cs" />
     <Compile Include="Providers\Roles\RoleAuditTrailEventProvider.cs" />
     <Compile Include="Providers\Users\UserAuditTrailEventProvider.cs" />
-    <Compile Include="Providers\Users\IUserEventHandler.cs" />
     <Compile Include="Providers\Users\UserEventHandler.cs" />
     <Compile Include="Settings\AuditTrailPartSettings.cs" />
     <Compile Include="Settings\AuditTrailPartSettingsEvents.cs" />
     <Compile Include="ViewModels\AuditTrailEventSummaryViewModel.cs" />
     <Compile Include="Drivers\AuditTrailPartDriver.cs" />
-    <Compile Include="Helpers\EventNameHelper.cs" />
+    <Compile Include="Helpers\EventNameExtensions.cs" />
     <Compile Include="Models\AuditTrailPart.cs" />
     <Compile Include="Services\AuditTrailEventDisplayBuilder.cs" />
     <Compile Include="Services\EventDataSerializer.cs" />
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/DiffGramAnalyzer.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/DiffGramAnalyzer.cs
index 5e5989b91..5eb08b657 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/DiffGramAnalyzer.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/DiffGramAnalyzer.cs
@@ -8,13 +8,11 @@ using Microsoft.XmlDiffPatch;
 namespace Orchard.AuditTrail.Providers.Content {
     public class DiffGramAnalyzer : IDiffGramAnalyzer {
         public XElement GenerateDiffGram(XElement element1, XElement element2) {
-            using(var node1Reader = element1.CreateReader())
+            using (var node1Reader = element1.CreateReader())
             using (var node2Reader = element2.CreateReader()) {
                 var result = new XDocument();
                 using (var writer = result.CreateWriter()) {
-                    var diff =
-                        new XmlDiff(XmlDiffOptions.IgnoreChildOrder | XmlDiffOptions.IgnoreWhitespace |
-                                    XmlDiffOptions.IgnoreComments | XmlDiffOptions.IgnoreXmlDecl);
+                    var diff = new XmlDiff(XmlDiffOptions.IgnoreChildOrder | XmlDiffOptions.IgnoreWhitespace | XmlDiffOptions.IgnoreComments | XmlDiffOptions.IgnoreXmlDecl);
                     diff.Compare(node1Reader, node2Reader, writer);
                     writer.Flush();
                     writer.Close();
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/IDiffGramAnalyzer.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/IDiffGramAnalyzer.cs
index 7482dd681..82631d36c 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/IDiffGramAnalyzer.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Content/IDiffGramAnalyzer.cs
@@ -9,8 +9,8 @@ namespace Orchard.AuditTrail.Providers.Content {
         XElement GenerateDiffGram(XElement element1, XElement element2);
 
         /// <summary>
-        /// Analyzes the specified DiffGram against the specified original XML element and returns a list of diff nodes,
-        /// where each node describes the difference between the original and updated document.
+        /// Analyzes the specified DiffGram element against the specified original XML element and returns a list of diff nodes,
+        /// where each node describes a difference between the original and updated document.
         /// </summary>
         IEnumerable<DiffNode> Analyze(XElement original, XElement diffGram);
     }
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/IRoleEventHandler.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/IRoleEventHandler.cs
deleted file mode 100644
index ddef5f9c0..000000000
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/IRoleEventHandler.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-using Orchard.Events;
-
-namespace Orchard.AuditTrail.Providers.Roles {
-    public interface IRoleEventHandler : IEventHandler {
-        void Created(dynamic context);
-        void Removed(dynamic context);
-        void Renamed(dynamic context);
-        void PermissionAdded(dynamic context);
-        void PermissionRemoved(dynamic context);
-        void UserAdded(dynamic context);
-        void UserRemoved(dynamic context);
-    }
-}
\ No newline at end of file
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/RoleEventHandler.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/RoleEventHandler.cs
index b63179143..49d040998 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/RoleEventHandler.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Roles/RoleEventHandler.cs
@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using Orchard.AuditTrail.Services;
 using Orchard.Environment.Extensions;
+using Orchard.Roles.Events;
 using Orchard.Security;
 
 namespace Orchard.AuditTrail.Providers.Roles {
@@ -14,38 +15,38 @@ namespace Orchard.AuditTrail.Providers.Roles {
             _wca = wca;
         }
 
-        public void Created(dynamic context) {
+        public void Created(RoleCreatedContext context) {
             RecordAuditTrailEvent(RoleAuditTrailEventProvider.Created, context.Role.Name);
         }
 
-        public void Removed(dynamic context) {
+        public void Removed(RoleRemovedContext context) {
             RecordAuditTrailEvent(RoleAuditTrailEventProvider.Removed, context.Role.Name);
         }
 
-        public void Renamed(dynamic context) {
+        public void Renamed(RoleRenamedContext context) {
             var eventData = new Dictionary<string, object> {
-                {"RoleName", (string)context.Role.Name},
-                {"PreviousRoleName", (string)context.PreviousRoleName},
-                {"NewRoleName", (string)context.NewRoleName},
+                {"RoleName", context.Role.Name},
+                {"PreviousRoleName", context.PreviousRoleName},
+                {"NewRoleName", context.NewRoleName},
             };
 
             RecordAuditTrailEvent(RoleAuditTrailEventProvider.Renamed, context.Role.Name, properties: null, eventData:eventData);
         }
 
-        public void PermissionAdded(dynamic context) {
-            RecordAuditTrailEvent(RoleAuditTrailEventProvider.PermissionAdded, (string) context.Role.Name, (IUser) context.Permission.Name);
+        public void PermissionAdded(PermissionAddedContext context) {
+            RecordAuditTrailEvent(RoleAuditTrailEventProvider.PermissionAdded, context.Role.Name);
         }
 
-        public void PermissionRemoved(dynamic context) {
-            RecordAuditTrailEvent(RoleAuditTrailEventProvider.PermissionRemoved, (string) context.Role.Name, (IUser) context.Permission.Name);
+        public void PermissionRemoved(PermissionRemovedContext context) {
+            RecordAuditTrailEvent(RoleAuditTrailEventProvider.PermissionRemoved, context.Role.Name);
         }
 
-        public void UserAdded(dynamic context) {
-            RecordAuditTrailEvent(RoleAuditTrailEventProvider.UserAdded, (string) context.Role.Name, (IUser) context.User);
+        public void UserAdded(UserAddedContext context) {
+            RecordAuditTrailEvent(RoleAuditTrailEventProvider.UserAdded, context.Role.Name, context.User);
         }
 
-        public void UserRemoved(dynamic context) {
-            RecordAuditTrailEvent(RoleAuditTrailEventProvider.UserRemoved, (string) context.Role.Name, (IUser) context.User);
+        public void UserRemoved(UserRemovedContext context) {
+            RecordAuditTrailEvent(RoleAuditTrailEventProvider.UserRemoved, context.Role.Name, context.User);
         }
 
         private void RecordAuditTrailEvent(string eventName, string roleName) {
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/IUserEventHandler.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/IUserEventHandler.cs
deleted file mode 100644
index 2b3342eb5..000000000
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/IUserEventHandler.cs
+++ /dev/null
@@ -1,27 +0,0 @@
-using Orchard.Events;
-using Orchard.Security;
-
-namespace Orchard.AuditTrail.Providers.Users {
-    public interface IUserEventHandler : IEventHandler {
-
-        /// <summary>
-        /// Called after a user has logged in.
-        /// </summary>
-        void LoggedIn(IUser user);
-
-        /// <summary>
-        /// Called when a user explicitly logs out (as opposed to one whose session cookie simply expires).
-        /// </summary>
-        void LoggedOut(IUser user);
-
-        /// <summary>
-        /// Called when a login attempt failed.
-        /// </summary>
-        void LogInFailed(string userNameOrEmail, string password);
-
-        /// <summary>
-        /// Called after a user has changed password.
-        /// </summary>
-        void ChangedPassword(IUser user);
-    }
-}
\ No newline at end of file
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/UserEventHandler.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/UserEventHandler.cs
index 449cd626c..61e6d1b95 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/UserEventHandler.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Providers/Users/UserEventHandler.cs
@@ -2,6 +2,7 @@
 using Orchard.AuditTrail.Services;
 using Orchard.Environment.Extensions;
 using Orchard.Security;
+using Orchard.Users.Events;
 
 namespace Orchard.AuditTrail.Providers.Users {
     [OrchardFeature("Orchard.AuditTrail.Users")]
@@ -47,5 +48,26 @@ namespace Orchard.AuditTrail.Providers.Users {
 
             _auditTrailManager.CreateRecord<UserAuditTrailEventProvider>(eventName, _wca.GetContext().CurrentUser, properties, eventData, eventFilterKey: "user", eventFilterData: user.UserName);
         }
+
+        public void Creating(UserContext context) {
+        }
+
+        public void Created(UserContext context) {
+        }
+
+        public void LoggingIn(string userNameOrEmail, string password) {
+        }
+
+        public void AccessDenied(IUser user) {
+        }
+
+        public void SentChallengeEmail(IUser user) {
+        }
+
+        public void ConfirmedEmail(IUser user) {
+        }
+
+        public void Approved(IUser user) {
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/AuditTrailManager.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/AuditTrailManager.cs
index d22a33f66..d05bd1a8f 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/AuditTrailManager.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/AuditTrailManager.cs
@@ -179,7 +179,7 @@ namespace Orchard.AuditTrail.Services {
         }
 
         public AuditTrailEventDescriptor DescribeEvent<T>(string eventName) where T:IAuditTrailEventProvider {
-            var fullyQualifiedEventName = EventNameHelper.GetFullyQualifiedEventName<T>(eventName);
+            var fullyQualifiedEventName = EventNameExtensions.GetFullyQualifiedEventName<T>(eventName);
             return DescribeEvent(fullyQualifiedEventName);
         }
 
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/Models/DescribeFor.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/Models/DescribeFor.cs
index 7d360a0a9..fed7d2aa4 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/Models/DescribeFor.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/Services/Models/DescribeFor.cs
@@ -32,7 +32,7 @@ namespace Orchard.AuditTrail.Services.Models {
                     Name = Name,
                     Events = Events
                 }, 
-                Event = EventNameHelper.GetFullyQualifiedEventName(provider.GetType(), eventName), 
+                Event = EventNameExtensions.GetFullyQualifiedEventName(provider.GetType(), eventName), 
                 Name = name, 
                 Description = description, 
                 IsEnabledByDefault = enableByDefault,
diff --git a/src/Orchard.Web/Modules/Orchard.AuditTrail/ViewModels/AuditTrailCategorySettingsViewModel.cs b/src/Orchard.Web/Modules/Orchard.AuditTrail/ViewModels/AuditTrailCategorySettingsViewModel.cs
index 04d619a08..81267c677 100644
--- a/src/Orchard.Web/Modules/Orchard.AuditTrail/ViewModels/AuditTrailCategorySettingsViewModel.cs
+++ b/src/Orchard.Web/Modules/Orchard.AuditTrail/ViewModels/AuditTrailCategorySettingsViewModel.cs
@@ -5,6 +5,6 @@ namespace Orchard.AuditTrail.ViewModels {
     public class AuditTrailCategorySettingsViewModel {
         public string Category { get; set; }
         public LocalizedString Name { get; set; }
-        public IList<AuditTrailEventSettingsViewModel> Events { get; set; }
+        public IEnumerable<AuditTrailEventSettingsViewModel> Events { get; set; }
     }
 }
\ No newline at end of file