diff --git a/Octokit/Http/JsonHttpPipeline.cs b/Octokit/Http/JsonHttpPipeline.cs
index 09e059ba..0793b123 100644
--- a/Octokit/Http/JsonHttpPipeline.cs
+++ b/Octokit/Http/JsonHttpPipeline.cs
@@ -11,6 +11,9 @@ namespace Octokit.Internal
     /// </summary>
     public class JsonHttpPipeline
     {
+        private const string moondragonPreviewApiVersion = "application/vnd.github.moondragon+json; charset=utf-8";
+        private const string v3ApiVersion = "application/vnd.github.v3+json; charset=utf-8";
+
         readonly IJsonSerializer _serializer;
 
         public JsonHttpPipeline() : this(new SimpleJsonSerializer())
@@ -30,7 +33,8 @@ namespace Octokit.Internal
 
             if (!request.Headers.ContainsKey("Accept"))
             {
-                request.Headers["Accept"] = "application/vnd.github.v3+json; charset=utf-8";
+
+                request.Headers["Accept"] = String.Join(",", new[]{v3ApiVersion, moondragonPreviewApiVersion}) ;
             }
             
             if (request.Method == HttpMethod.Get || request.Body == null) return;