diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 22959e57..8b941069 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,6 +1,6 @@
 {
   "name": "Octokit.Webhooks",
-  "image": "mcr.microsoft.com/devcontainers/dotnet:dev-8.0",
+  "image": "mcr.microsoft.com/devcontainers/dotnet:dev-9.0",
   "postCreateCommand": "dotnet restore",
   "features": {
     "ghcr.io/devcontainers/features/dotnet": {
diff --git a/global.json b/global.json
index 94afb036..eba86d0e 100644
--- a/global.json
+++ b/global.json
@@ -1,7 +1,7 @@
 {
   "sdk": {
     "rollForward": "latestFeature",
-    "allowPrerelease": false,
-    "version": "8.0.403"
+    "allowPrerelease": true,
+    "version": "9.0.100-rc.2.24474.11"
   }
 }
diff --git a/src/Octokit.Webhooks/Converter/StringEnumEnumerableConverter.cs b/src/Octokit.Webhooks/Converter/StringEnumEnumerableConverter.cs
index 6b687ba1..7fdbcae9 100644
--- a/src/Octokit.Webhooks/Converter/StringEnumEnumerableConverter.cs
+++ b/src/Octokit.Webhooks/Converter/StringEnumEnumerableConverter.cs
@@ -33,13 +33,13 @@ private static List<StringEnum<TEnum>> ReadInternal(ref Utf8JsonReader reader)
         {
             if (reader.TokenType != JsonTokenType.StartArray)
             {
-                returnValue.Add((StringEnum<TEnum>)JsonSerializer.Deserialize(ref reader, typeof(StringEnum<TEnum>), Options)!);
+                returnValue.Add(JsonSerializer.Deserialize<StringEnum<TEnum>>(ref reader, Options)!);
             }
 
-            reader.Read();
+            _ = reader.Read();
         }
 
-        return returnValue!;
+        return returnValue;
     }
 
     private static void WriteInternal(Utf8JsonWriter writer, IEnumerable<StringEnum<TEnum>> value)