diff --git a/src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/ActivityDescriptor.cs b/src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/ActivityDescriptor.cs
index 4f6b68a1d..b66b0090d 100644
--- a/src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/ActivityDescriptor.cs
+++ b/src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/ActivityDescriptor.cs
@@ -10,17 +10,17 @@ public record ActivityDescriptor
     /// <summary>
     /// The fully qualified name of the activity type.
     /// </summary>
-    public string TypeName { get; init; } = default!;
+    public string TypeName { get; init; } = null!;
 
     /// <summary>
     /// The namespace of the activity type.
     /// </summary>
-    public string Namespace { get; init; } = default!;
+    public string Namespace { get; init; } = null!;
     
     /// <summary>
     /// The name of the activity type.
     /// </summary>
-    public string Name { get; init; } = default!;
+    public string Name { get; init; } = null!;
     
     /// <summary>
     /// The version of the activity type.
@@ -30,7 +30,7 @@ public record ActivityDescriptor
     /// <summary>
     /// The category of the activity type.
     /// </summary>
-    public string Category { get; init; } = default!;
+    public string Category { get; init; } = null!;
     
     /// <summary>
     /// The display name of the activity type.
diff --git a/src/modules/Elsa.Workflows.Core/Attributes/ActivityAttribute.cs b/src/modules/Elsa.Workflows.Core/Attributes/ActivityAttribute.cs
index 068ad408b..d01b59cc9 100644
--- a/src/modules/Elsa.Workflows.Core/Attributes/ActivityAttribute.cs
+++ b/src/modules/Elsa.Workflows.Core/Attributes/ActivityAttribute.cs
@@ -8,21 +8,21 @@ public class ActivityAttribute : Attribute
         // Default constructor.
     }
     
-    public ActivityAttribute(string @namespace, string? category, string? description = default)
+    public ActivityAttribute(string @namespace, string? category, string? description = null)
     {
         Namespace = @namespace;
         Description = description;
         Category = category;
     }
 
-    public ActivityAttribute(string @namespace, string? description = default)
+    public ActivityAttribute(string @namespace, string? description = null)
     {
         Namespace = @namespace;
         Description = description;
         Category = @namespace;
     }
 
-    public ActivityAttribute(string @namespace, string? type, int version = 1, string? description = default, string? category = default)
+    public ActivityAttribute(string @namespace, string? type, int version = 1, string? description = null, string? category = null)
     {
         Namespace = @namespace;
         Type = type;
@@ -38,4 +38,5 @@ public class ActivityAttribute : Attribute
     public string? DisplayName { get; set; }
     public string? Category { get; set; }
     public ActivityKind Kind { get; set; } = ActivityKind.Action;
+    public bool RunAsynchronously { get; set; }
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.Workflows.Core/Attributes/TaskActivityAttribute.cs b/src/modules/Elsa.Workflows.Core/Attributes/TaskActivityAttribute.cs
deleted file mode 100644
index 390cfd628..000000000
--- a/src/modules/Elsa.Workflows.Core/Attributes/TaskActivityAttribute.cs
+++ /dev/null
@@ -1,19 +0,0 @@
-namespace Elsa.Workflows.Attributes;
-
-[AttributeUsage(AttributeTargets.Class)]
-public class TaskActivityAttribute : ActivityAttribute
-{
-    public TaskActivityAttribute()
-    {
-        Kind = ActivityKind.Task;
-    }
-    
-    public TaskActivityAttribute(string @namespace, string? category, string? description = null, bool runAsynchronously = false) 
-        : base(@namespace, category, description)
-    {
-        Kind = ActivityKind.Task;
-        RunAsynchronously = runAsynchronously;
-    }
-    
-    public bool RunAsynchronously { get; set; }
-}
\ No newline at end of file
diff --git a/src/modules/Elsa.Workflows.Core/Models/ActivityConstructorContext.cs b/src/modules/Elsa.Workflows.Core/Models/ActivityConstructorContext.cs
index 2e36b9859..38f35415b 100644
--- a/src/modules/Elsa.Workflows.Core/Models/ActivityConstructorContext.cs
+++ b/src/modules/Elsa.Workflows.Core/Models/ActivityConstructorContext.cs
@@ -49,24 +49,13 @@ public static class JsonActivityConstructorContextHelper
 
         // 7) Pull out your boolean flags from the cleaned element
         var canStartWorkflow = GetBoolean(cleanedElement, "canStartWorkflow");
-        var runAsynchronously = GetNullableBoolean(cleanedElement, "runAsynchronously");
-        if (runAsynchronously is null)
-        {
-            if (activityDescriptor.Attributes.OfType<TaskActivityAttribute>().FirstOrDefault() is { } taskActivityAttribute)
-            {
-                runAsynchronously = taskActivityAttribute.RunAsynchronously;
-            }
-            else
-            {
-                runAsynchronously = false;
-            }
-        }
+        var runAsynchronously = GetNullableBoolean(cleanedElement, "runAsynchronously") ?? activityDescriptor.RunAsynchronously;
 
         // 8) If composite, setup
         if (activity is IComposite composite)
             composite.Setup();
 
-        // 9) Your existing synthetic inputs/outputs routines, using the cleanedElement
+        // 9) Existing synthetic inputs/outputs routines, using the cleanedElement
         ReadSyntheticInputs(activityDescriptor, activity, cleanedElement, serializerOptions);
         ReadSyntheticOutputs(activityDescriptor, activity, cleanedElement);
 
diff --git a/src/modules/Elsa.Workflows.Core/Models/ActivityDescriptor.cs b/src/modules/Elsa.Workflows.Core/Models/ActivityDescriptor.cs
index 89f214934..8b6cf8675 100644
--- a/src/modules/Elsa.Workflows.Core/Models/ActivityDescriptor.cs
+++ b/src/modules/Elsa.Workflows.Core/Models/ActivityDescriptor.cs
@@ -76,6 +76,11 @@ public class ActivityDescriptor
     /// </summary>
     public ActivityKind Kind { get; set; } = ActivityKind.Action;
     
+    /// <summary>
+    /// Whether the activity should be executed asynchronously. Applies only when the Kind is set to Task and as a default when not set on the activity itself.
+    /// </summary>
+    public bool RunAsynchronously { get; set; }
+    
     /// <summary>
     /// The ports of the activity type.
     /// </summary>
diff --git a/src/modules/Elsa.Workflows.Runtime/Middleware/Activities/BackgroundActivityInvokerMiddleware.cs b/src/modules/Elsa.Workflows.Runtime/Middleware/Activities/BackgroundActivityInvokerMiddleware.cs
index 30277beb9..05242c9eb 100644
--- a/src/modules/Elsa.Workflows.Runtime/Middleware/Activities/BackgroundActivityInvokerMiddleware.cs
+++ b/src/modules/Elsa.Workflows.Runtime/Middleware/Activities/BackgroundActivityInvokerMiddleware.cs
@@ -117,15 +117,7 @@ public class BackgroundActivityInvokerMiddleware(
             return false;
         
         var runAsynchronously = activity.GetRunAsynchronously();
-
-        if (runAsynchronously is null)
-        {
-            var taskActivityAttribute = activityDescriptor.Attributes.OfType<TaskActivityAttribute>().FirstOrDefault();
-            
-            return taskActivityAttribute is { RunAsynchronously: true };
-        }
-
-        return (bool)runAsynchronously;
+        return runAsynchronously ?? activityDescriptor.RunAsynchronously;
     }
 
     private static bool GetIsBackgroundExecution(ActivityExecutionContext context) => context.TransientProperties.ContainsKey(BackgroundActivityExecutionContextExtensions.IsBackgroundExecution);