diff --git a/libnm/libnm.ver b/libnm/libnm.ver
index 8100f3b631..2209452a6a 100644
--- a/libnm/libnm.ver
+++ b/libnm/libnm.ver
@@ -1604,3 +1604,8 @@ global:
 	nm_tc_qdisc_get_attribute_names;
 	nm_tc_qdisc_set_attribute;
 } libnm_1_16_0;
+
+libnm_1_20_0 {
+global:
+	nm_device_modem_get_device_id;
+} libnm_1_18_0;
diff --git a/libnm/nm-device-modem.c b/libnm/nm-device-modem.c
index 0373b3c08a..8fd54b8ca4 100644
--- a/libnm/nm-device-modem.c
+++ b/libnm/nm-device-modem.c
@@ -36,12 +36,14 @@ G_DEFINE_TYPE (NMDeviceModem, nm_device_modem, NM_TYPE_DEVICE)
 typedef struct {
 	NMDeviceModemCapabilities caps;
 	NMDeviceModemCapabilities current_caps;
+	char *device_id;
 } NMDeviceModemPrivate;
 
 enum {
 	PROP_0,
 	PROP_MODEM_CAPS,
 	PROP_CURRENT_CAPS,
+	PROP_DEVICE_ID,
 	LAST_PROP
 };
 
@@ -82,6 +84,26 @@ nm_device_modem_get_current_capabilities (NMDeviceModem *self)
 	return NM_DEVICE_MODEM_GET_PRIVATE (self)->current_caps;
 }
 
+/**
+ * nm_device_modem_get_device_id:
+ * @self: a #NMDeviceModem
+ *
+ * An identifier used by the modem backend (ModemManager) that aims to
+ * uniquely identify the a device. Can be used to match a connection to a
+ * particular device.
+ *
+ * Returns: a device-id string
+ *
+ * Since: 1.20
+ **/
+const char *
+nm_device_modem_get_device_id (NMDeviceModem *self)
+{
+	g_return_val_if_fail (NM_IS_DEVICE_MODEM (self), NULL);
+
+	return NM_DEVICE_MODEM_GET_PRIVATE (self)->device_id;
+}
+
 static const char *
 get_type_description (NMDevice *device)
 {
@@ -164,6 +186,7 @@ init_dbus (NMObject *object)
 	const NMPropertiesInfo property_info[] = {
 		{ NM_DEVICE_MODEM_MODEM_CAPABILITIES,   &priv->caps },
 		{ NM_DEVICE_MODEM_CURRENT_CAPABILITIES, &priv->current_caps },
+		{ NM_DEVICE_MODEM_DEVICE_ID,            &priv->device_id },
 		{ NULL },
 	};
 
@@ -174,6 +197,16 @@ init_dbus (NMObject *object)
 	                                property_info);
 }
 
+static void
+finalize (GObject *object)
+{
+	NMDeviceModemPrivate *priv = NM_DEVICE_MODEM_GET_PRIVATE (object);
+
+	g_free (priv->device_id);
+
+	G_OBJECT_CLASS (nm_device_modem_parent_class)->finalize (object);
+}
+
 static void
 get_property (GObject *object,
               guint prop_id,
@@ -189,6 +222,9 @@ get_property (GObject *object,
 	case PROP_CURRENT_CAPS:
 		g_value_set_flags (value, nm_device_modem_get_current_capabilities (self));
 		break;
+	case PROP_DEVICE_ID:
+		g_value_set_string (value, nm_device_modem_get_device_id (self));
+		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 		break;
@@ -205,6 +241,7 @@ nm_device_modem_class_init (NMDeviceModemClass *modem_class)
 	g_type_class_add_private (modem_class, sizeof (NMDeviceModemPrivate));
 
 	/* virtual methods */
+	object_class->finalize = finalize;
 	object_class->get_property = get_property;
 
 	nm_object_class->init_dbus = init_dbus;
@@ -242,4 +279,17 @@ nm_device_modem_class_init (NMDeviceModemClass *modem_class)
 		                     NM_DEVICE_MODEM_CAPABILITY_NONE,
 		                     G_PARAM_READABLE |
 		                     G_PARAM_STATIC_STRINGS));
+
+	/**
+	 * NMDeviceModem:device-id:
+	 *
+	 * Since: 1.20
+	 **/
+	g_object_class_install_property
+		(object_class, PROP_CURRENT_CAPS,
+		 g_param_spec_string (NM_DEVICE_MODEM_DEVICE_ID, "", "",
+		                     NULL,
+		                     G_PARAM_READABLE |
+		                     G_PARAM_STATIC_STRINGS));
+
 }
diff --git a/libnm/nm-device-modem.h b/libnm/nm-device-modem.h
index a5af03460d..588851fd71 100644
--- a/libnm/nm-device-modem.h
+++ b/libnm/nm-device-modem.h
@@ -39,6 +39,7 @@ G_BEGIN_DECLS
 
 #define NM_DEVICE_MODEM_MODEM_CAPABILITIES   "modem-capabilities"
 #define NM_DEVICE_MODEM_CURRENT_CAPABILITIES "current-capabilities"
+#define NM_DEVICE_MODEM_DEVICE_ID            "device-id"
 
 /**
  * NMDeviceModem:
@@ -59,6 +60,9 @@ GType nm_device_modem_get_type (void);
 NMDeviceModemCapabilities nm_device_modem_get_modem_capabilities (NMDeviceModem *self);
 NMDeviceModemCapabilities nm_device_modem_get_current_capabilities (NMDeviceModem *self);
 
+NM_AVAILABLE_IN_1_20
+const char *nm_device_modem_get_device_id (NMDeviceModem *self);
+
 G_END_DECLS
 
 #endif /* __NM_DEVICE_MODEM_H__ */