diff --git a/HandyIpc.Generator/ClientProxy.cs b/HandyIpc.Generator/ClientProxy.cs
index a28eb3e..2eed384 100644
--- a/HandyIpc.Generator/ClientProxy.cs
+++ b/HandyIpc.Generator/ClientProxy.cs
@@ -30,17 +30,19 @@ public class {nameof(ClientProxy)}{className}{typeParameters} : {interfaceType}
         private readonly Sender _sender;
         private readonly ISerializer _serializer;
         private readonly string _key;
+{Text(events.Any() ? @"
         private readonly AwaiterManager _awaiterManager;
+" : RemoveLineIfEmpty)}
 
 {events.For(item => $@"
         private event {item.Type.ToTypeDeclaration()} _{item.Name};
 ")}
-
 {events.For(item =>
             {
-                var eSymbol = ((INamedTypeSymbol)item.Type).DelegateInvokeMethod!.Parameters[1];
+                IParameterSymbol eSymbol = ((INamedTypeSymbol)item.Type).DelegateInvokeMethod!.Parameters[1];
                 string eType = eSymbol.Type.ToTypeDeclaration();
                 return $@"
+
         public event {item.Type.ToTypeDeclaration()} {item.Name}
         {{
             add
@@ -65,7 +67,6 @@ public class {nameof(ClientProxy)}{className}{typeParameters} : {interfaceType}
                 }}
             }}
         }}
-
 ";
             })}
 
@@ -74,7 +75,9 @@ public class {nameof(ClientProxy)}{className}{typeParameters} : {interfaceType}
             _sender = sender;
             _serializer = serializer;
             _key = key;
+{Text(events.Any() ? @"
             _awaiterManager = new AwaiterManager(key, sender, serializer);
+" : RemoveLineIfEmpty)}
         }}
 {methods.For(method =>
 {
diff --git a/HandyIpc.Generator/Dispatcher.cs b/HandyIpc.Generator/Dispatcher.cs
index cab5de2..16ff318 100644
--- a/HandyIpc.Generator/Dispatcher.cs
+++ b/HandyIpc.Generator/Dispatcher.cs
@@ -26,7 +26,7 @@ namespace {@namespace}
     [global::System.Diagnostics.DebuggerNonUserCode]
     [global::System.Reflection.Obfuscation(Exclude = true)]
     [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
-    public class {nameof(Dispatcher)}{className}{typeParameters} : IMethodDispatcher
+    public class {nameof(Dispatcher)}{className}{typeParameters} : IMethodDispatcher{(events.Any() ? ", INotifiable" : null)}
 {@interface.TypeParameters.For(typeParameter => $@"
         {typeParameter.ToGenericConstraint()}
 ")}
@@ -36,8 +36,10 @@ public class {nameof(Dispatcher)}{className}{typeParameters} : IMethodDispatcher
         private readonly Lazy<IReadOnlyDictionary<string, MethodInfo>> _genericMethodMapping;
 " : RemoveLineIfEmpty)}
 
-        public NotifierManager NotifierManager {{ get; set; }}
+{Text(events.Any() ? @"
+        public NotifierManager NotifierManager { get; set; }
 
+" : RemoveLineIfEmpty)}
         public {nameof(Dispatcher)}{className}({interfaceType} instance)
         {{
             _instance = instance;
@@ -45,10 +47,9 @@ public class {nameof(Dispatcher)}{className}{typeParameters} : IMethodDispatcher
             _genericMethodMapping = new Lazy<IReadOnlyDictionary<string, MethodInfo>>(
                 () => GeneratorHelper.GetGenericMethodMapping(typeof({interfaceType}), _instance));
 " : RemoveLineIfEmpty)}
-
 {events.For(item => $@"
             instance.{item.Name} += (_, e) => NotifierManager.Publish(""{item.Name}"", e);
-", RemoveLineIfEmpty)}
+")}
         }}
 
         public async Task Dispatch(Context ctx, Func<Task> next)
diff --git a/HandyIpc.Tests/EventTypeTest.cs b/HandyIpc.Tests/EventTypeTest.cs
index 597eb3c..0f39140 100644
--- a/HandyIpc.Tests/EventTypeTest.cs
+++ b/HandyIpc.Tests/EventTypeTest.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Threading.Tasks;
 using HandyIpc;
 using HandyIpcTests.Fixtures;
 using HandyIpcTests.Interfaces;
diff --git a/HandyIpc/ContainerServerBuilder.cs b/HandyIpc/ContainerServerBuilder.cs
index 3243a24..40e4105 100644
--- a/HandyIpc/ContainerServerBuilder.cs
+++ b/HandyIpc/ContainerServerBuilder.cs
@@ -54,9 +54,13 @@ public IContainerServer Build()
             ConcurrentDictionary<string, NotifierManager> notifiers = new();
             foreach (var (key, type, factory) in _interfaceMap)
             {
-                IMethodDispatcher dispatcher = CreateDispatcher(type, factory);
-                dispatcher.NotifierManager = notifiers.GetOrAdd(key, _ => new NotifierManager(_serializerFactory()));
-                Middleware methodDispatcher = dispatcher.Dispatch;
+                object dispatcher = CreateDispatcher(type, factory);
+                if (dispatcher is INotifiable notifiable)
+                {
+                    notifiable.NotifierManager = notifiers.GetOrAdd(key, _ => new NotifierManager(_serializerFactory()));
+                }
+
+                Middleware methodDispatcher = ((IMethodDispatcher)dispatcher).Dispatch;
                 map.Add(key, methodDispatcher);
             }
 
@@ -65,11 +69,15 @@ public IContainerServer Build()
                 Middleware methodDispatcher = Middlewares.GetMethodDispatcher(
                     genericTypes =>
                     {
-                        IMethodDispatcher dispatcher = CreateDispatcher(
+                        object dispatcher = CreateDispatcher(
                             type.MakeGenericType(genericTypes),
                             () => factory(genericTypes));
-                        dispatcher.NotifierManager = notifiers.GetOrAdd(key, _ => new NotifierManager(_serializerFactory()));
-                        return dispatcher;
+                        if (dispatcher is INotifiable notifiable)
+                        {
+                            notifiable.NotifierManager = notifiers.GetOrAdd(key, _ => new NotifierManager(_serializerFactory()));
+                        }
+
+                        return (IMethodDispatcher)dispatcher;
                     });
                 map.Add(key, methodDispatcher);
             }
@@ -78,13 +86,13 @@ public IContainerServer Build()
                 Middlewares.Heartbeat,
                 Middlewares.ExceptionHandler,
                 Middlewares.GetHandleRequest(map),
-                Middlewares.GetHandleEvent(notifiers),
+                Middlewares.GetHandleSubscription(notifiers),
                 Middlewares.NotFound);
 
             return new ContainerServer(_serverFactory(), middleware, _serializerFactory(), _loggerFactory());
         }
 
-        private static IMethodDispatcher CreateDispatcher(Type interfaceType, Func<object> factory)
+        private static object CreateDispatcher(Type interfaceType, Func<object> factory)
         {
             object instance = factory();
 
@@ -105,9 +113,7 @@ private static IMethodDispatcher CreateDispatcher(Type interfaceType, Func<objec
             // this does not lead to naming conflicts even if the user also declares a Dispatch method
             // with the same signature in the IContract interface.
             object proxy = Activator.CreateInstance(interfaceType.GetServerProxyType(), instance);
-            var dispatcher = (IMethodDispatcher)Activator.CreateInstance(interfaceType.GetDispatcherType(), proxy);
-
-            return dispatcher;
+            return Activator.CreateInstance(interfaceType.GetDispatcherType(), proxy);
         }
     }
 }
diff --git a/HandyIpc/Core/AsyncPool.cs b/HandyIpc/Core/AsyncPool.cs
index 4de76db..360d1a2 100644
--- a/HandyIpc/Core/AsyncPool.cs
+++ b/HandyIpc/Core/AsyncPool.cs
@@ -8,10 +8,10 @@ public sealed class AsyncPool<TValue> : PoolBase<TValue> where TValue : IDisposa
         private readonly Func<Task<TValue>> _factory;
         private readonly Func<TValue, Task<bool>> _checkValue;
 
-        public AsyncPool(Func<Task<TValue>> factory, Func<TValue, Task<bool>>? checkValue = null)
+        public AsyncPool(Func<Task<TValue>> factory, Func<TValue, Task<bool>> checkValue)
         {
             _factory = factory;
-            _checkValue = checkValue ?? (_ => Task.FromResult(true));
+            _checkValue = checkValue;
         }
 
         public async Task<RentedValue<TValue>> RentAsync()
diff --git a/HandyIpc/Core/IMethodDispatcher.cs b/HandyIpc/Core/IMethodDispatcher.cs
index e50803e..bc85617 100644
--- a/HandyIpc/Core/IMethodDispatcher.cs
+++ b/HandyIpc/Core/IMethodDispatcher.cs
@@ -5,8 +5,6 @@ namespace HandyIpc.Core
 {
     public interface IMethodDispatcher
     {
-        NotifierManager NotifierManager { get; set; }
-
         Task Dispatch(Context context, Func<Task> next);
     }
 }
diff --git a/HandyIpc/Core/INotifiable.cs b/HandyIpc/Core/INotifiable.cs
new file mode 100644
index 0000000..139b170
--- /dev/null
+++ b/HandyIpc/Core/INotifiable.cs
@@ -0,0 +1,7 @@
+namespace HandyIpc.Core
+{
+    public interface INotifiable
+    {
+        NotifierManager NotifierManager { get; set; }
+    }
+}
diff --git a/HandyIpc/Core/Middlewares.cs b/HandyIpc/Core/Middlewares.cs
index 1c0ba38..e6e3ac6 100644
--- a/HandyIpc/Core/Middlewares.cs
+++ b/HandyIpc/Core/Middlewares.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -54,7 +53,7 @@ public static Middleware GetHandleRequest(IReadOnlyDictionary<string, Middleware
             };
         }
 
-        public static Middleware GetHandleEvent(ConcurrentDictionary<string, NotifierManager> notifiers)
+        public static Middleware GetHandleSubscription(IReadOnlyDictionary<string, NotifierManager> notifiers)
         {
             return async (ctx, next) =>
             {
@@ -64,12 +63,14 @@ public static Middleware GetHandleEvent(ConcurrentDictionary<string, NotifierMan
                     {
                         case SubscriptionType.Add:
                             {
-                                var manager = notifiers.GetOrAdd(subscription.Name, _ => new NotifierManager(ctx.Serializer));
-                                manager.Subscribe(subscription.CallbackName, subscription.ProcessId, ctx.Connection);
-                                ctx.Output = Signals.Unit;
-                                ctx.KeepAlive = false;
+                                if (notifiers.TryGetValue(subscription.Name, out NotifierManager manager))
+                                {
+                                    manager.Subscribe(subscription.CallbackName, subscription.ProcessId, ctx.Connection);
+                                    ctx.Output = Signals.Unit;
+                                    ctx.KeepAlive = false;
+                                }
                             }
-                            break;
+                            return;
                         case SubscriptionType.Remove:
                             {
                                 if (notifiers.TryGetValue(subscription.Name, out NotifierManager manager))
@@ -79,10 +80,8 @@ public static Middleware GetHandleEvent(ConcurrentDictionary<string, NotifierMan
 
                                 ctx.Output = Signals.Unit;
                             }
-                            break;
+                            return;
                     }
-
-                    return;
                 }
 
                 await next();
diff --git a/HandyIpc/Core/Pool.cs b/HandyIpc/Core/Pool.cs
index 3b7dc10..adb1e9f 100644
--- a/HandyIpc/Core/Pool.cs
+++ b/HandyIpc/Core/Pool.cs
@@ -7,10 +7,10 @@ public sealed class Pool<TValue> : PoolBase<TValue> where TValue : IDisposable
         private readonly Func<TValue> _factory;
         private readonly Func<TValue, bool> _checkValue;
 
-        public Pool(Func<TValue> factory, Func<TValue, bool>? checkValue = null)
+        public Pool(Func<TValue> factory, Func<TValue, bool> checkValue)
         {
             _factory = factory;
-            _checkValue = checkValue ?? (_ => true);
+            _checkValue = checkValue;
         }
 
         public RentedValue<TValue> Rent()
diff --git a/HandyIpc/Core/Subscription.cs b/HandyIpc/Core/Subscription.cs
index 3ce7146..96169d9 100644
--- a/HandyIpc/Core/Subscription.cs
+++ b/HandyIpc/Core/Subscription.cs
@@ -1,10 +1,9 @@
-using System;
 using System.Diagnostics;
 using System.Text;
 
 namespace HandyIpc.Core
 {
-    public enum SubscriptionType { Add, Promise, Remove }
+    public enum SubscriptionType { Add, Remove }
 
     public class Subscription
     {
@@ -19,7 +18,7 @@ public class Subscription
 
         public string CallbackName { get; set; } = string.Empty;
 
-        public int ProcessId { get; } = InnerProcessId;
+        public int ProcessId => InnerProcessId;
 
         internal static bool TryParse(byte[] bytes, ISerializer serializer, out Subscription subscription)
         {
@@ -45,11 +44,6 @@ internal static byte[] Add(string key, string name, ISerializer serializer)
             return GetBytes(SubscriptionType.Add, key, name, serializer);
         }
 
-        internal static byte[] Promise(string key, string name, ISerializer serializer)
-        {
-            return GetBytes(SubscriptionType.Promise, key, name, serializer);
-        }
-
         internal static byte[] Remove(string key, string name, ISerializer serializer)
         {
             return GetBytes(SubscriptionType.Remove, key, name, serializer);