diff --git a/src/modem.c b/src/modem.c
index e966a6e4..553549e4 100644
--- a/src/modem.c
+++ b/src/modem.c
@@ -1075,6 +1075,7 @@ static const struct {
 	{ OFONO_MESSAGE_MANAGER_INTERFACE,		"sms"	},
 	{ OFONO_SIM_MANAGER_INTERFACE,			"sim"	},
 	{ OFONO_STK_INTERFACE,				"stk"	},
+	{ OFONO_SUPPLEMENTARY_SERVICES_INTERFACE,	"ussd"	},
 	{ OFONO_CONNECTION_MANAGER_INTERFACE,		"gprs"	},
 	{ OFONO_TEXT_TELEPHONY_INTERFACE,		"tty"	},
 	{ OFONO_LOCATION_REPORTING_INTERFACE,		"gps"	},