diff --git a/HTTP/Responses/NotAcceptable.cs b/HTTP/Responses/NotAcceptable.cs
new file mode 100644
index 0000000..e8a7949
--- /dev/null
+++ b/HTTP/Responses/NotAcceptable.cs
@@ -0,0 +1,11 @@
+namespace Uwaa.HTTP.Responses;
+
+/// <summary>
+/// An error caused by a client requesting an unavailable format.
+/// </summary>
+public class NotAcceptable : HttpResponse
+{
+    public NotAcceptable(HttpContent? body = null) : base(406, "Not Acceptable", body)
+    {
+    }
+}