diff --git a/activitystreams/attachment.go b/activitystreams/attachment.go
index c2bfc2e..d221169 100644
--- a/activitystreams/attachment.go
+++ b/activitystreams/attachment.go
@@ -1,33 +1,33 @@
 package activitystreams
 
 import (
 	"mime"
 	"strings"
 )
 
 type Attachment struct {
 	Type      AttachmentType `json:"type"`
 	URL       string         `json:"url"`
 	MediaType string         `json:"mediaType"`
 	Name      string         `json:"name"`
 }
 
 type AttachmentType string
 
 const AttachImage AttachmentType = "Image"
 
 // NewImageAttachment creates a new Attachment from the given URL, setting the
 // correct type and automatically detecting the MediaType based on the file
 // extension.
-func NewImageAttachment(url string) *Attachment {
+func NewImageAttachment(url string) Attachment {
 	var imgType string
 	extIdx := strings.LastIndexByte(url, '.')
 	if extIdx > -1 {
 		imgType = mime.TypeByExtension(url[extIdx:])
 	}
-	return &Attachment{
+	return Attachment{
 		Type:      AttachImage,
 		URL:       url,
 		MediaType: imgType,
 	}
 }