diff --git a/src/ngircd/irc-mode.c b/src/ngircd/irc-mode.c
index f91a28c6..8da4a65a 100644
--- a/src/ngircd/irc-mode.c
+++ b/src/ngircd/irc-mode.c
@@ -256,6 +256,14 @@ Client_Mode( CLIENT *Client, REQUEST *Req, CLIENT *Origin, CLIENT *Target )
 							ERR_RESTRICTED_MSG,
 							Client_ID(Origin));
 			break;
+		case 'R': /* Registered (not [un]settable by clients) */
+			if (Client_Type(Client) == CLIENT_SERVER)
+				x[0] = 'R';
+			else
+				ok = IRC_WriteStrClient(Origin,
+							ERR_NICKREGISTER_MSG,
+							Client_ID(Origin));
+			break;
 		case 'x': /* Cloak hostname */
 			if (Client_HasMode(Client, 'r'))
 				ok = IRC_WriteStrClient(Origin,
diff --git a/src/ngircd/messages.h b/src/ngircd/messages.h
index 53637b44..da861f9a 100644
--- a/src/ngircd/messages.h
+++ b/src/ngircd/messages.h
@@ -138,6 +138,7 @@
 #define ERR_CHANOPRIVSNEEDED_MSG	"482 %s %s :You are not channel operator"
 #define ERR_CANTKILLSERVER_MSG		"483 %s :You can't kill a server!"
 #define ERR_RESTRICTED_MSG		"484 %s :Your connection is restricted"
+#define ERR_NICKREGISTER_MSG		"484 %s :Cannot modify user mode (+R) -- Use IRC services"
 #define ERR_NOOPERHOST_MSG		"491 %s :Not configured for your host"
 #define ERR_NOTONSAMECHANNEL_MSG	"493 %s :You must share a common channel with %s"