diff --git a/src/nm-device-interface.c b/src/nm-device-interface.c
index a040a5a9a9..3462defcbc 100644
--- a/src/nm-device-interface.c
+++ b/src/nm-device-interface.c
@@ -315,35 +315,6 @@ nm_device_interface_activate (NMDeviceInterface *device,
 	return success;
 }
 
-gboolean
-nm_device_interface_disconnect (NMDeviceInterface *device,
-                                GError **error)
-{
-	NMDeviceState state;
-	gboolean success = FALSE;
-
-	g_return_val_if_fail (NM_IS_DEVICE_INTERFACE (device), FALSE);
-
-	g_object_get (G_OBJECT (device), "state", &state, NULL);
-
-	switch (state) {
-	case NM_DEVICE_STATE_UNKNOWN:
-	case NM_DEVICE_STATE_UNMANAGED:
-	case NM_DEVICE_STATE_UNAVAILABLE:
-	case NM_DEVICE_STATE_DISCONNECTED:
-		g_set_error_literal (error,
-		                     NM_DEVICE_INTERFACE_ERROR,
-		                     NM_DEVICE_INTERFACE_ERROR_NOT_ACTIVE,
-		                     "Cannot disconnect an inactive device.");
-		break;
-	default:
-		success = NM_DEVICE_INTERFACE_GET_INTERFACE (device)->disconnect (device, error);
-		break;
-	}
-
-	return success;
-}
-
 static void
 impl_device_disconnect (NMDeviceInterface *device,
                         DBusGMethodInvocation *context)
diff --git a/src/nm-device-interface.h b/src/nm-device-interface.h
index 299b9f86ee..c6a65121bf 100644
--- a/src/nm-device-interface.h
+++ b/src/nm-device-interface.h
@@ -98,7 +98,6 @@ struct _NMDeviceInterface {
 	                      GError **error);
 
 	void (*deactivate) (NMDeviceInterface *device, NMDeviceStateReason reason);
-	gboolean (*disconnect) (NMDeviceInterface *device, GError **error);
 
 	/* Signals */
 	void (*state_changed) (NMDeviceInterface *device,
@@ -110,8 +109,6 @@ struct _NMDeviceInterface {
 GQuark nm_device_interface_error_quark (void);
 GType nm_device_interface_error_get_type (void);
 
-gboolean nm_device_interface_disconnect (NMDeviceInterface *device, GError **error);
-
 GType nm_device_interface_get_type (void);
 
 gboolean nm_device_interface_activate (NMDeviceInterface *device,
diff --git a/src/nm-device.c b/src/nm-device.c
index 215a370279..a8a7f258c1 100644
--- a/src/nm-device.c
+++ b/src/nm-device.c
@@ -172,7 +172,6 @@ static gboolean nm_device_activate (NMDeviceInterface *device,
                                     NMActRequest *req,
                                     GError **error);
 static void nm_device_deactivate (NMDeviceInterface *device, NMDeviceStateReason reason);
-static gboolean device_disconnect (NMDeviceInterface *device, GError **error);
 
 static void nm_device_take_down (NMDevice *dev, gboolean wait, NMDeviceStateReason reason);
 
@@ -201,7 +200,6 @@ device_interface_init (NMDeviceInterface *device_interface_class)
 	/* interface implementation */
 	device_interface_class->activate = nm_device_activate;
 	device_interface_class->deactivate = nm_device_deactivate;
-	device_interface_class->disconnect = device_disconnect;
 }
 
 
@@ -2982,14 +2980,27 @@ nm_device_deactivate (NMDeviceInterface *device, NMDeviceStateReason reason)
 	nm_device_set_ip6_config (self, NULL, FALSE, &ignored);
 }
 
-static gboolean
-device_disconnect (NMDeviceInterface *device,
-                   GError **error)
+gboolean
+nm_device_disconnect (NMDevice *device, GError **error)
 {
-	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (NM_DEVICE (device));
+	NMDevicePrivate *priv;
+
+	g_return_val_if_fail (device != NULL, FALSE);
+	g_return_val_if_fail (NM_IS_DEVICE (device), FALSE);
+
+	priv = NM_DEVICE_GET_PRIVATE (device);
+	if (priv->state <= NM_DEVICE_STATE_DISCONNECTED) {
+		g_set_error_literal (error,
+		                     NM_DEVICE_INTERFACE_ERROR,
+		                     NM_DEVICE_INTERFACE_ERROR_NOT_ACTIVE,
+		                     "Cannot disconnect an inactive device.");
+		return FALSE;
+	}
 
 	priv->autoconnect_inhibit = TRUE;	
-	nm_device_state_changed (NM_DEVICE (device), NM_DEVICE_STATE_DISCONNECTED, NM_DEVICE_STATE_REASON_USER_REQUESTED);
+	nm_device_state_changed (device,
+	                         NM_DEVICE_STATE_DISCONNECTED,
+	                         NM_DEVICE_STATE_REASON_USER_REQUESTED);
 	return TRUE;
 }
 
diff --git a/src/nm-device.h b/src/nm-device.h
index 146d20201a..f8260d866e 100644
--- a/src/nm-device.h
+++ b/src/nm-device.h
@@ -188,7 +188,6 @@ void nm_device_set_managed (NMDevice *device,
 
 void nm_device_clear_autoconnect_inhibit (NMDevice *device);
 
-
 void nm_device_handle_autoip4_event (NMDevice *self,
                                      const char *event,
                                      const char *address);
@@ -199,6 +198,8 @@ void nm_device_state_changed (NMDevice *device,
 
 gboolean nm_device_get_firmware_missing (NMDevice *self);
 
+gboolean nm_device_disconnect (NMDevice *device, GError **error);
+
 G_END_DECLS
 
 #endif	/* NM_DEVICE_H */
diff --git a/src/nm-manager.c b/src/nm-manager.c
index b8e5188e9c..f30ac3f47c 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -1409,7 +1409,7 @@ disconnect_net_auth_done_cb (NMAuthChain *chain,
 	error = deactivate_disconnect_check_error (auth_error, result, "Disconnect");
 	if (!error) {
 		device = nm_auth_chain_get_data (chain, "device");
-		if (!nm_device_interface_disconnect (NM_DEVICE_INTERFACE (device), &error))
+		if (!nm_device_disconnect (device, &error))
 			g_assert (error);
 	}
 
@@ -1461,7 +1461,7 @@ manager_device_disconnect_request (NMDevice *device,
 
 	/* Yay for root */
 	if (0 == sender_uid) {
-		if (!nm_device_interface_disconnect (NM_DEVICE_INTERFACE (device), &error)) {
+		if (!nm_device_disconnect (device, &error)) {
 			dbus_g_method_return_error (context, error);
 			g_clear_error (&error);
 		} else