diff --git a/RestSharp.IntegrationTests/MultipartFormDataTests.cs b/RestSharp.IntegrationTests/MultipartFormDataTests.cs
index 611fb11ff..f13448b41 100644
--- a/RestSharp.IntegrationTests/MultipartFormDataTests.cs
+++ b/RestSharp.IntegrationTests/MultipartFormDataTests.cs
@@ -3,6 +3,7 @@
     using System;
     using System.IO;
     using System.Net;
+    using System.Threading;
 
     using RestSharp.IntegrationTests.Helpers;
 
@@ -58,6 +59,84 @@ public void MultipartFormData()
             }
         }
 
+        [Fact]
+        public void AlwaysMultipartFormData_WithParameter_Execute()
+        {
+            const string baseUrl = "http://localhost:8888/";
+
+            using (SimpleServer.Create(baseUrl, EchoHandler))
+            {
+                var client = new RestClient(baseUrl);
+                var request = new RestRequest("?json_route=/posts")
+                                  {
+                                      AlwaysMultipartFormData = true,
+                                      Method = Method.POST,
+                                  };
+                request.AddParameter("title", "test", ParameterType.RequestBody);
+
+                var response = client.Execute(request);
+                Assert.Null(response.ErrorException);
+            }
+        }
+
+        [Fact]
+        public void AlwaysMultipartFormData_WithParameter_ExecuteTaskAsync()
+        {
+            const string baseUrl = "http://localhost:8888/";
+
+            using (SimpleServer.Create(baseUrl, EchoHandler))
+            {
+                var client = new RestClient(baseUrl);
+                var request = new RestRequest("?json_route=/posts")
+                                  {
+                                      AlwaysMultipartFormData = true,
+                                      Method = Method.POST,
+                                  };
+                request.AddParameter("title", "test", ParameterType.RequestBody);
+
+                var task = client.ExecuteTaskAsync(request).ContinueWith(
+                    x =>
+                        {
+                            Assert.Null(x.Result.ErrorException);
+                        });
+
+                task.Wait();
+            }
+        }
+
+        [Fact]
+        public void AlwaysMultipartFormData_WithParameter_ExecuteAsync()
+        {
+            const string baseUrl = "http://localhost:8888/";
+
+            using (SimpleServer.Create(baseUrl, EchoHandler))
+            {
+                var client = new RestClient(baseUrl);
+                var request = new RestRequest("?json_route=/posts")
+                {
+                    AlwaysMultipartFormData = true,
+                    Method = Method.POST,
+                };
+                request.AddParameter("title", "test", ParameterType.RequestBody);
+                IRestResponse syncResponse = null;
+
+                using (var eventWaitHandle = new AutoResetEvent(false))
+                {
+                    client.ExecuteAsync(
+                        request,
+                        response =>
+                        {
+                            syncResponse = response;
+                            eventWaitHandle.Set();
+                        });
+
+                    eventWaitHandle.WaitOne();
+                }
+
+                Assert.Null(syncResponse.ErrorException);
+            }
+        }
+
         private static void EchoHandler(HttpListenerContext obj)
         {
             obj.Response.StatusCode = 200;
diff --git a/RestSharp/Http.Sync.cs b/RestSharp/Http.Sync.cs
index c11e46163..a13965008 100644
--- a/RestSharp/Http.Sync.cs
+++ b/RestSharp/Http.Sync.cs
@@ -140,7 +140,7 @@ private HttpResponse PostPutInternal(string method)
         {
             var webRequest = ConfigureWebRequest(method, Url);
 
-            PreparePostData(webRequest);
+            PreparePostBody(webRequest);
 
             WriteRequestBody(webRequest);
             return GetResponse(webRequest);
@@ -214,33 +214,29 @@ private static HttpWebResponse GetRawResponse(HttpWebRequest request)
             }
         }
 
-        private void PreparePostData(HttpWebRequest webRequest)
+        private void WriteRequestBody(HttpWebRequest webRequest)
         {
-            if (HasFiles || AlwaysMultipartFormData)
+            if (HasBody || HasFiles || AlwaysMultipartFormData)
             {
-                webRequest.ContentType = GetMultipartFormContentType();
-
-                using (var requestStream = webRequest.GetRequestStream())
-                {
-                    WriteMultipartFormData(requestStream);
-                }
+#if !WINDOWS_PHONE && !PocketPC
+                webRequest.ContentLength = CalculateContentLength();
+#endif
             }
 
-            PreparePostBody(webRequest);
-        }
-
-        private void WriteRequestBody(HttpWebRequest webRequest)
-        {
-            if (!HasBody)
-                return;
-
-            var bytes = this.RequestBodyBytes ?? this.Encoding.GetBytes(this.RequestBody);
-
-            webRequest.ContentLength = bytes.Length;
-
             using (var requestStream = webRequest.GetRequestStream())
             {
-                requestStream.Write(bytes, 0, bytes.Length);
+                if (HasFiles || AlwaysMultipartFormData)
+                {
+                    WriteMultipartFormData(requestStream);
+                }
+                else if (RequestBodyBytes != null)
+                {
+                    requestStream.Write(RequestBodyBytes, 0, RequestBodyBytes.Length);
+                }
+                else
+                {
+                    WriteStringTo(requestStream, RequestBody);
+                }
             }
         }