diff --git a/activitystreams/tag.go b/activitystreams/tag.go
index 63fe4c4..38010bf 100644
--- a/activitystreams/tag.go
+++ b/activitystreams/tag.go
@@ -1,14 +1,14 @@
 package activitystreams
 
 type Tag struct {
 	Type TagType `json:"type"`
 	HRef string  `json:"href"`
 	Name string  `json:"name"`
 }
 
 type TagType string
 
 const (
 	TagHashtag TagType = "Hashtag"
-	TagMention         = "Mention"
+	TagMention TagType = "Mention"
 )