diff --git a/Assets/Mirror/Core/NetworkClient.cs b/Assets/Mirror/Core/NetworkClient.cs
index c7699a059..e1362c1a5 100644
--- a/Assets/Mirror/Core/NetworkClient.cs
+++ b/Assets/Mirror/Core/NetworkClient.cs
@@ -552,14 +552,17 @@ public static void RegisterHandler<T>(Action<T, int> handler, bool requireAuthen
             handlers[msgType] = NetworkMessages.WrapHandler((Action<NetworkConnection, T, int>)HandlerWrapped, requireAuthentication, exceptionsDisconnect);
         }
 
-        /// <summary>Replace a handler for a particular message type. Should require authentication by default.</summary>
-        // RegisterHandler throws a warning (as it should) if a handler is assigned twice
-        // Use of ReplaceHandler makes it clear the user intended to replace the handler
+        // Deprecated 2024-01-21
+        [Obsolete("Use ReplaceHandler without the NetworkConnection parameter instead. This version is obsolete and will be removed soon.")]
         public static void ReplaceHandler<T>(Action<NetworkConnection, T> handler, bool requireAuthentication = true)
             where T : struct, NetworkMessage
         {
+            // we use the same WrapHandler function for server and client.
+            // so let's wrap it to ignore the NetworkConnection parameter.
+            // it's not needed on client. it's always NetworkClient.connection.
             ushort msgType = NetworkMessageId<T>.Id;
-            handlers[msgType] = NetworkMessages.WrapHandler(handler, requireAuthentication, exceptionsDisconnect);
+            void HandlerWrapped(NetworkConnection _, T value) => handler(_, value);
+            handlers[msgType] = NetworkMessages.WrapHandler((Action<NetworkConnection, T>)HandlerWrapped, requireAuthentication, exceptionsDisconnect);
         }
 
         /// <summary>Replace a handler for a particular message type. Should require authentication by default.</summary>
@@ -568,7 +571,26 @@ public static void ReplaceHandler<T>(Action<NetworkConnection, T> handler, bool
         public static void ReplaceHandler<T>(Action<T> handler, bool requireAuthentication = true)
             where T : struct, NetworkMessage
         {
-            ReplaceHandler((NetworkConnection _, T value) => { handler(value); }, requireAuthentication);
+            // we use the same WrapHandler function for server and client.
+            // so let's wrap it to ignore the NetworkConnection parameter.
+            // it's not needed on client. it's always NetworkClient.connection.
+            ushort msgType = NetworkMessageId<T>.Id;
+            void HandlerWrapped(NetworkConnection _, T value) => handler(value);
+            handlers[msgType] = NetworkMessages.WrapHandler((Action<NetworkConnection, T>)HandlerWrapped, requireAuthentication, exceptionsDisconnect);
+        }
+
+        /// <summary>Replace a handler for a particular message type. Should require authentication by default. This version passes channelId to the handler.</summary>
+        // RegisterHandler throws a warning (as it should) if a handler is assigned twice
+        // Use of ReplaceHandler makes it clear the user intended to replace the handler
+        public static void ReplaceHandler<T>(Action<T, int> handler, bool requireAuthentication = true)
+            where T : struct, NetworkMessage
+        {
+            // we use the same WrapHandler function for server and client.
+            // so let's wrap it to ignore the NetworkConnection parameter.
+            // it's not needed on client. it's always NetworkClient.connection.
+            ushort msgType = NetworkMessageId<T>.Id;
+            void HandlerWrapped(NetworkConnection _, T value, int channelId) => handler(value, channelId);
+            handlers[msgType] = NetworkMessages.WrapHandler((Action<NetworkConnection, T, int>)HandlerWrapped, requireAuthentication, exceptionsDisconnect);
         }
 
         /// <summary>Unregister a message handler of type T.</summary>