diff --git a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/api/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub.netstandard2.0.cs b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/api/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub.netstandard2.0.cs
index ee553b8d299cd..0fb76e2439423 100644
--- a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/api/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub.netstandard2.0.cs
+++ b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/api/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub.netstandard2.0.cs
@@ -169,7 +169,7 @@ public UserEventResponse() { }
         public UserEventResponse(System.BinaryData data, Microsoft.Azure.Functions.Worker.WebPubSubDataType dataType) { }
         public UserEventResponse(string data, Microsoft.Azure.Functions.Worker.WebPubSubDataType dataType = Microsoft.Azure.Functions.Worker.WebPubSubDataType.Text) { }
         [System.Text.Json.Serialization.JsonPropertyNameAttribute("states")]
-        public System.Collections.Generic.IReadOnlyDictionary<string, System.BinaryData> ConnectionStates { get { throw null; } set { } }
+        public System.Collections.Generic.IReadOnlyDictionary<string, System.BinaryData> ConnectionStates { get { throw null; } }
         [System.Text.Json.Serialization.JsonPropertyNameAttribute("data")]
         public System.BinaryData Data { get { throw null; } set { } }
         [System.Text.Json.Serialization.JsonPropertyNameAttribute("dataType")]
diff --git a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/ConnectEventResponse.cs b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/ConnectEventResponse.cs
index 2dd1c8f07bda6..cfe700cd4005d 100644
--- a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/ConnectEventResponse.cs
+++ b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/ConnectEventResponse.cs
@@ -6,6 +6,7 @@
 using System.ComponentModel;
 using System.Linq;
 using System.Text.Json.Serialization;
+using Microsoft.Azure.WebPubSub.Common;
 
 namespace Microsoft.Azure.Functions.Worker
 {
@@ -35,6 +36,7 @@ internal override WebPubSubStatusCode StatusCode
         /// The connection states.
         /// </summary>
         [JsonPropertyName("states")]
+        [JsonConverter(typeof(ConnectionStatesConverter))]
         public IReadOnlyDictionary<string, BinaryData> ConnectionStates => _states;
 
         /// <summary>
diff --git a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/UserEventResponse.cs b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/UserEventResponse.cs
index 801a0377dcd78..92c57e61f4821 100644
--- a/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/UserEventResponse.cs
+++ b/sdk/webpubsub/Microsoft.Azure.Functions.Worker.Extensions.WebPubSub/src/Models/Trigger/UserEventResponse.cs
@@ -6,6 +6,7 @@
 using System.ComponentModel;
 using System.Runtime.Serialization;
 using System.Text.Json.Serialization;
+using Microsoft.Azure.WebPubSub.Common;
 
 namespace Microsoft.Azure.Functions.Worker
 {
@@ -36,7 +37,8 @@ internal override WebPubSubStatusCode StatusCode
         /// The connection states.
         /// </summary>
         [JsonPropertyName("states")]
-        public IReadOnlyDictionary<string, BinaryData> ConnectionStates { get; set; }
+        [JsonConverter(typeof(ConnectionStatesConverter))]
+        public IReadOnlyDictionary<string, BinaryData> ConnectionStates => _states;
 
         /// <summary>
         /// Message.