diff --git a/api-response.go b/api-response.go
index 9b982510b..da29f25ff 100644
--- a/api-response.go
+++ b/api-response.go
@@ -502,10 +502,11 @@ func writeErrorResponse(w http.ResponseWriter, req *http.Request, errorCode APIE
 	setCommonHeaders(w)
 	// write Header
 	w.WriteHeader(error.HTTPStatusCode)
-	writeErrorResponseNoHeader(w, req, error, resource)
+	writeErrorResponseNoHeader(w, req, errorCode, resource)
 }
 
-func writeErrorResponseNoHeader(w http.ResponseWriter, req *http.Request, error APIError, resource string) {
+func writeErrorResponseNoHeader(w http.ResponseWriter, req *http.Request, errorCode APIErrorCode, resource string) {
+	error := getAPIError(errorCode)
 	// Generate error response.
 	errorResponse := getAPIErrorResponse(error, resource)
 	encodedErrorResponse := encodeResponse(errorResponse)
diff --git a/object-handlers.go b/object-handlers.go
index 5a42e0a2a..7da414277 100644
--- a/object-handlers.go
+++ b/object-handlers.go
@@ -974,6 +974,14 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 	// Send 200 OK
 	setCommonHeaders(w)
 	w.WriteHeader(http.StatusOK)
+	// Xml headers need to be sent before we possibly send whitespace characters
+	// to the client.
+	_, err = w.Write([]byte(xml.Header))
+	if err != nil {
+		errorIf(err, "Unable to write XML header for complete multipart upload")
+		writeErrorResponseNoHeader(w, r, ErrInternalError, r.URL.Path)
+		return
+	}
 
 	doneCh := make(chan struct{})
 	// Signal that completeMultipartUpload is over via doneCh
@@ -992,7 +1000,7 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 			writePartSmallErrorResponse(w, r, oErr)
 		default:
 			// Handle all other generic issues.
-			writeErrorResponseNoHeader(w, r, getAPIError(toAPIErrorCode(err)), r.URL.Path)
+			writeErrorResponseNoHeader(w, r, toAPIErrorCode(err), r.URL.Path)
 		}
 		return
 	}
@@ -1001,7 +1009,12 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 	location := getLocation(r)
 	// Generate complete multipart response.
 	response := generateCompleteMultpartUploadResponse(bucket, object, location, md5Sum)
-	encodedSuccessResponse := encodeResponse(response)
+	encodedSuccessResponse, err := xml.Marshal(response)
+	if err != nil {
+		errorIf(err, "Unable to parse CompleteMultipartUpload response")
+		writeErrorResponseNoHeader(w, r, ErrInternalError, r.URL.Path)
+		return
+	}
 	// write success response.
 	w.Write(encodedSuccessResponse)
 	w.(http.Flusher).Flush()