diff --git a/Octokit/Clients/CommitCommentReactionsClient.cs b/Octokit/Clients/CommitCommentReactionsClient.cs
index 8e867d24..000cddb5 100644
--- a/Octokit/Clients/CommitCommentReactionsClient.cs
+++ b/Octokit/Clients/CommitCommentReactionsClient.cs
@@ -25,7 +25,7 @@ namespace Octokit
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNull(reaction, "reaction");
 
-            return ApiConnection.Post<Reaction>(ApiUrls.CommitCommentReactions(owner, name, number), reaction.ToParametersDictionary(), AcceptHeaders.ReactionsPreview);
+            return ApiConnection.Post<Reaction>(ApiUrls.CommitCommentReactions(owner, name, number), reaction, AcceptHeaders.ReactionsPreview);
         }
 
         /// <summary>
diff --git a/Octokit/Clients/IssueCommentReactionsClient.cs b/Octokit/Clients/IssueCommentReactionsClient.cs
index 37ee8370..352475d5 100644
--- a/Octokit/Clients/IssueCommentReactionsClient.cs
+++ b/Octokit/Clients/IssueCommentReactionsClient.cs
@@ -26,7 +26,7 @@ namespace Octokit
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNull(reaction, "reaction");
 
-            return ApiConnection.Post<Reaction>(ApiUrls.IssueCommentReactions(owner, name, number), reaction.ToParametersDictionary(), AcceptHeaders.ReactionsPreview);
+            return ApiConnection.Post<Reaction>(ApiUrls.IssueCommentReactions(owner, name, number), reaction, AcceptHeaders.ReactionsPreview);
         }
 
         /// <summary>
diff --git a/Octokit/Clients/IssueReactionsClient.cs b/Octokit/Clients/IssueReactionsClient.cs
index 5a9f9e01..d630bfce 100644
--- a/Octokit/Clients/IssueReactionsClient.cs
+++ b/Octokit/Clients/IssueReactionsClient.cs
@@ -26,7 +26,7 @@ namespace Octokit
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNull(reaction, "reaction");
 
-            return ApiConnection.Post<Reaction>(ApiUrls.IssueReactions(owner, name, number), reaction.ToParametersDictionary(), AcceptHeaders.ReactionsPreview);
+            return ApiConnection.Post<Reaction>(ApiUrls.IssueReactions(owner, name, number), reaction, AcceptHeaders.ReactionsPreview);
         }
 
         /// <summary>
diff --git a/Octokit/Clients/PullRequestReviewCommentReactionsClient.cs b/Octokit/Clients/PullRequestReviewCommentReactionsClient.cs
index 71635150..4c07dffa 100644
--- a/Octokit/Clients/PullRequestReviewCommentReactionsClient.cs
+++ b/Octokit/Clients/PullRequestReviewCommentReactionsClient.cs
@@ -26,7 +26,7 @@ namespace Octokit
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNull(reaction, "reaction");
 
-            return ApiConnection.Post<Reaction>(ApiUrls.PullRequestReviewCommentReaction(owner, name, number), reaction.ToParametersDictionary(), AcceptHeaders.ReactionsPreview);
+            return ApiConnection.Post<Reaction>(ApiUrls.PullRequestReviewCommentReaction(owner, name, number), reaction, AcceptHeaders.ReactionsPreview);
         }
 
         /// <summary>
diff --git a/Octokit/Http/SimpleJsonSerializer.cs b/Octokit/Http/SimpleJsonSerializer.cs
index b05db410..fcc4371b 100644
--- a/Octokit/Http/SimpleJsonSerializer.cs
+++ b/Octokit/Http/SimpleJsonSerializer.cs
@@ -78,7 +78,7 @@ namespace Octokit.Internal
                 Justification = "The API expects lowercase values")]
             protected override object SerializeEnum(Enum p)
             {
-                return p.ToString().ToLowerInvariant();
+                return p.ToParameter();
             }
 
             private string _type;
diff --git a/Octokit/Models/Request/NewReaction.cs b/Octokit/Models/Request/NewReaction.cs
index d55f1721..7434da0c 100644
--- a/Octokit/Models/Request/NewReaction.cs
+++ b/Octokit/Models/Request/NewReaction.cs
@@ -4,7 +4,7 @@ using System.Globalization;
 namespace Octokit
 {
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
-    public class NewReaction : RequestParameters
+    public class NewReaction
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="NewReaction"/> class.
@@ -18,7 +18,7 @@ namespace Octokit
         /// <summary>
         /// The reaction type (required)
         /// </summary>
-        public ReactionType Content { get; private set; }        
+        public ReactionType Content { get; private set; }
 
         internal string DebuggerDisplay
         {