diff --git a/activitystreams/activity.go b/activitystreams/activity.go
index b1a5340..a94de75 100644
--- a/activitystreams/activity.go
+++ b/activitystreams/activity.go
@@ -5,7 +5,8 @@ import (
 )
 
 const (
-	toPublic = "https://www.w3.org/ns/activitystreams#Public"
+	Namespace = "https://www.w3.org/ns/activitystreams"
+	toPublic  = "https://www.w3.org/ns/activitystreams#Public"
 )
 
 type Activity struct {
@@ -21,7 +22,7 @@ func NewCreateActivity(o *Object) *Activity {
 	a := Activity{
 		BaseObject: BaseObject{
 			Context: []interface{}{
-				"https://www.w3.org/ns/activitystreams",
+				Namespace,
 			},
 			ID:   o.ID + "/activity",
 			Type: "Create",
diff --git a/activitystreams/data.go b/activitystreams/data.go
index e107d36..4197171 100644
--- a/activitystreams/data.go
+++ b/activitystreams/data.go
@@ -38,7 +38,7 @@ func NewOrderedCollection(accountRoot, collType string, items int) *OrderedColle
 	oc := OrderedCollection{
 		BaseObject: BaseObject{
 			Context: []interface{}{
-				"https://www.w3.org/ns/activitystreams",
+				Namespace,
 			},
 			ID:   accountRoot + "/" + collType,
 			Type: "OrderedCollection",
@@ -62,7 +62,7 @@ func NewOrderedCollectionPage(accountRoot, collType string, items, page int) *Or
 	ocp := OrderedCollectionPage{
 		BaseObject: BaseObject{
 			Context: []interface{}{
-				"https://www.w3.org/ns/activitystreams",
+				Namespace,
 			},
 			ID:   fmt.Sprintf("%s/%s?page=%d", accountRoot, collType, page),
 			Type: "OrderedCollectionPage",
diff --git a/activitystreams/person.go b/activitystreams/person.go
index 7b93726..b878d2c 100644
--- a/activitystreams/person.go
+++ b/activitystreams/person.go
@@ -20,7 +20,7 @@ func NewPerson(accountRoot string) *Person {
 		BaseObject: BaseObject{
 			Type: "Person",
 			Context: []interface{}{
-				"https://www.w3.org/ns/activitystreams",
+				Namespace,
 			},
 			ID: accountRoot,
 		},