diff --git a/const.go b/const.go
index a18b427..4717ad8 100644
--- a/const.go
+++ b/const.go
@@ -7,6 +7,7 @@ package main
 const (
 	VERSION          = "0.4.0-devel"
 	nsEme            = "urn:xmpp:eme:0"
+	nsHints          = "urn:xmpp:hints"
 	nsHttpUpload     = "urn:xmpp:http:upload:0"
 	nsJabberClient   = "jabber:client"
 	nsJabberData     = "jabber:x:data"
diff --git a/iqstructs.go b/iqstructs.go
index 6cc69f1..4d61170 100644
--- a/iqstructs.go
+++ b/iqstructs.go
@@ -12,6 +12,10 @@ type OxMessageElement struct {
 	Text    string   `xml:",chardata"`
 	To      string   `xml:"to,attr"`
 	Id      string   `xml:"id,attr"`
+	Store   struct {
+		Text  string `xml:",chardata"`
+		Xmlns string `xml:"xmlns,attr"`
+	} `xml:"store"`
 	Openpgp struct {
 		Text  string `xml:",chardata"`
 		Xmlns string `xml:"xmlns,attr"`
diff --git a/ox.go b/ox.go
index 5f9fb3b..0a2aece 100644
--- a/ox.go
+++ b/ox.go
@@ -511,6 +511,7 @@ func oxEncrypt(client *xmpp.Client, oxPrivKey *crypto.Key, recipient string,
 	}
 	oxMessage.To = recipient
 	oxMessage.Id = getID()
+	oxMessage.Store.Xmlns = nsHints
 	oxMessage.Openpgp.Text = base64.StdEncoding.EncodeToString(pgpMessage.Data)
 	oxMessage.Openpgp.Xmlns = nsOx
 	oxMessage.Encryption.Xmlns = nsEme