diff --git a/src/core/Elsa.Core/Services/ActivityResolver.cs b/src/core/Elsa.Core/Services/ActivityResolver.cs
index 88e19ed65..e50ccbfcc 100644
--- a/src/core/Elsa.Core/Services/ActivityResolver.cs
+++ b/src/core/Elsa.Core/Services/ActivityResolver.cs
@@ -18,7 +18,7 @@ namespace Elsa.Services
                 () =>
                 {
                     var activities = activitiesFunc();
-                    return activities.Select(x => x.GetType()).ToDictionary(x => x.Name);
+                    return activities.Select(x => x.GetType()).Distinct().ToDictionary(x => x.Name);
                 });
         }
 
diff --git a/src/samples/Sample12/Program.cs b/src/samples/Sample12/Program.cs
index 904e0ef80..b39044c5d 100644
--- a/src/samples/Sample12/Program.cs
+++ b/src/samples/Sample12/Program.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using System.Threading.Tasks;
 using Elsa.Activities.Console.Extensions;
@@ -48,7 +48,6 @@ namespace Sample12
             return new ServiceCollection()
                 .AddElsa()
                 .AddConsoleActivities()
-                .AddUserTaskActivities()
                 .AddWorkflow<UserTaskWorkflow>()
                 .BuildServiceProvider();
         }