diff --git a/src/clients/Elsa.Api.Client/Helpers/RefitSettingsHelper.cs b/src/clients/Elsa.Api.Client/Helpers/RefitSettingsHelper.cs
index 8a87220a3..fafd23891 100644
--- a/src/clients/Elsa.Api.Client/Helpers/RefitSettingsHelper.cs
+++ b/src/clients/Elsa.Api.Client/Helpers/RefitSettingsHelper.cs
@@ -1,6 +1,9 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
 using Elsa.Api.Client.Converters;
+using Elsa.Api.Client.Resources.Alterations.Contracts;
+using Elsa.Api.Client.Resources.Alterations.Models;
 using Refit;
 
 namespace Elsa.Api.Client;
@@ -34,6 +37,27 @@ public static class RefitSettingsHelper
         options.Converters.Add(new VersionOptionsJsonConverter());
         options.Converters.Add(new TypeJsonConverter());
 
+        var alterationTypes = new[] { typeof(Cancel) };
+
+        options.TypeInfoResolver = new DefaultJsonTypeInfoResolver()
+            .WithAddedModifier(typeInfo =>
+            {
+                if (typeInfo.Type != typeof(IAlteration))
+                    return;
+
+                if (typeInfo.Kind != JsonTypeInfoKind.Object)
+                    return;
+
+                var polymorphismOptions = new JsonPolymorphismOptions { TypeDiscriminatorPropertyName = "type" };
+
+                foreach (var alterationType in alterationTypes.ToList())
+                {
+                    polymorphismOptions.DerivedTypes.Add(new(alterationType, alterationType.Name));
+                }
+
+                typeInfo.PolymorphismOptions = polymorphismOptions;
+            });
+
         configureJsonSerializerOptions?.Invoke(serviceProvider, options);
 
         return options;
diff --git a/src/clients/Elsa.Api.Client/Resources/Alterations/Models/Cancel.cs b/src/clients/Elsa.Api.Client/Resources/Alterations/Models/Cancel.cs
new file mode 100644
index 000000000..45b2c836d
--- /dev/null
+++ b/src/clients/Elsa.Api.Client/Resources/Alterations/Models/Cancel.cs
@@ -0,0 +1,6 @@
+namespace Elsa.Api.Client.Resources.Alterations.Models;
+
+/// <summary>
+/// Cancels the workflow instances in an alteration plan.
+/// </summary>
+public class Cancel : AlterationBase;
\ No newline at end of file
diff --git a/src/modules/Elsa.Alterations.Core/Serialization/AlterationSerializationOptionConfigurator.cs b/src/modules/Elsa.Alterations.Core/Serialization/AlterationSerializationOptionConfigurator.cs
index d5614b6d9..217331a5f 100644
--- a/src/modules/Elsa.Alterations.Core/Serialization/AlterationSerializationOptionConfigurator.cs
+++ b/src/modules/Elsa.Alterations.Core/Serialization/AlterationSerializationOptionConfigurator.cs
@@ -1,4 +1,3 @@
-using System.Text.Json;
 using System.Text.Json.Serialization;
 using System.Text.Json.Serialization.Metadata;
 using Elsa.Alterations.Core.Contracts;
@@ -35,7 +34,7 @@ public class AlterationSerializationOptionConfigurator(IOptions<AlterationOption
 
             foreach (var alterationType in alterationTypes.ToList())
             {
-                polymorphismOptions.DerivedTypes.Add(new JsonDerivedType(alterationType, alterationType.Name));
+                polymorphismOptions.DerivedTypes.Add(new(alterationType, alterationType.Name));
             }
 
             typeInfo.PolymorphismOptions = polymorphismOptions;
diff --git a/src/modules/Elsa.Alterations/Activities/CompleteAlterationPlan.cs b/src/modules/Elsa.Alterations/Activities/CompleteAlterationPlan.cs
index b63cd9715..17ec70101 100644
--- a/src/modules/Elsa.Alterations/Activities/CompleteAlterationPlan.cs
+++ b/src/modules/Elsa.Alterations/Activities/CompleteAlterationPlan.cs
@@ -13,7 +13,7 @@ namespace Elsa.Alterations.Activities;
 /// Marks an alteration plan as completed.
 /// </summary>
 [Browsable(false)]
-[Activity("Elsa", "Alterations", "Dispatches jobs for the specified Alteration Plan", Kind = ActivityKind.Job)]
+[Activity("Elsa", "Alterations", "Dispatches jobs for the specified Alteration Plan", Kind = ActivityKind.Task)]
 public class CompleteAlterationPlan : CodeActivity
 {
     /// <inheritdoc />
diff --git a/src/modules/Elsa.Alterations/Activities/DispatchAlterationJobs.cs b/src/modules/Elsa.Alterations/Activities/DispatchAlterationJobs.cs
index a8c2c6fe5..a22a45652 100644
--- a/src/modules/Elsa.Alterations/Activities/DispatchAlterationJobs.cs
+++ b/src/modules/Elsa.Alterations/Activities/DispatchAlterationJobs.cs
@@ -15,7 +15,7 @@ namespace Elsa.Alterations.Activities;
 /// Submits an alteration plan for execution.
 /// </summary>
 [Browsable(false)]
-[Activity("Elsa", "Alterations", "Dispatches jobs for the specified Alteration Plan", Kind = ActivityKind.Job)]
+[Activity("Elsa", "Alterations", "Dispatches jobs for the specified Alteration Plan", Kind = ActivityKind.Task)]
 public class DispatchAlterationJobs : CodeActivity
 {
     /// <inheritdoc />
diff --git a/src/modules/Elsa.Alterations/Activities/GenerateAlterationJobs.cs b/src/modules/Elsa.Alterations/Activities/GenerateAlterationJobs.cs
index fd2357501..03a68cca5 100644
--- a/src/modules/Elsa.Alterations/Activities/GenerateAlterationJobs.cs
+++ b/src/modules/Elsa.Alterations/Activities/GenerateAlterationJobs.cs
@@ -20,7 +20,7 @@ namespace Elsa.Alterations.Activities;
 /// Submits an alteration plan for execution.
 /// </summary>
 [Browsable(false)]
-[Activity("Elsa", "Alterations", "Generates jobs for the specified Alteration Plan", Kind = ActivityKind.Job)]
+[Activity("Elsa", "Alterations", "Generates jobs for the specified Alteration Plan", Kind = ActivityKind.Task)]
 public class GenerateAlterationJobs : CodeActivity<int>
 {
     /// <inheritdoc />
diff --git a/src/modules/Elsa.Alterations/AlterationHandlers/CancelHandler.cs b/src/modules/Elsa.Alterations/AlterationHandlers/CancelHandler.cs
new file mode 100644
index 000000000..38bc32404
--- /dev/null
+++ b/src/modules/Elsa.Alterations/AlterationHandlers/CancelHandler.cs
@@ -0,0 +1,22 @@
+using Elsa.Alterations.AlterationTypes;
+using Elsa.Alterations.Core.Abstractions;
+using Elsa.Alterations.Core.Contexts;
+using JetBrains.Annotations;
+
+namespace Elsa.Alterations.AlterationHandlers;
+
+/// <summary>
+/// Upgrades the version of the workflow instance.
+/// </summary>
+[UsedImplicitly]
+public class CancelHandler : AlterationHandlerBase<Cancel>
+{
+    /// <inheritdoc />
+    protected override ValueTask HandleAsync(AlterationContext context, Cancel alteration)
+    {
+        context.WorkflowExecutionContext.Cancel();
+        
+        context.Succeed();
+        return ValueTask.CompletedTask;
+    }
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.Alterations/AlterationTypes/Cancel.cs b/src/modules/Elsa.Alterations/AlterationTypes/Cancel.cs
new file mode 100644
index 000000000..c0a5f7fde
--- /dev/null
+++ b/src/modules/Elsa.Alterations/AlterationTypes/Cancel.cs
@@ -0,0 +1,10 @@
+using Elsa.Alterations.Core.Abstractions;
+using JetBrains.Annotations;
+
+namespace Elsa.Alterations.AlterationTypes;
+
+/// <summary>
+/// Cancels the workflow instances in an alteration plan.
+/// </summary>
+[UsedImplicitly]
+public class Cancel : AlterationBase;
\ No newline at end of file
diff --git a/src/modules/Elsa.Alterations/Extensions/ServiceCollectionExtensions.cs b/src/modules/Elsa.Alterations/Extensions/ServiceCollectionExtensions.cs
index 76a6818b8..b930d2878 100644
--- a/src/modules/Elsa.Alterations/Extensions/ServiceCollectionExtensions.cs
+++ b/src/modules/Elsa.Alterations/Extensions/ServiceCollectionExtensions.cs
@@ -20,6 +20,7 @@ public static class ServiceCollectionExtensions
         services.AddAlteration<ModifyVariable, ModifyVariableHandler>();
         services.AddAlteration<ScheduleActivity, ScheduleActivityHandler>();
         services.AddAlteration<CancelActivity, CancelActivityHandler>();
+        services.AddAlteration<Cancel, CancelHandler>();
         services.AddNotificationHandlersFrom<AlterationsFeature>();
         return services;
     }