diff --git a/src/fu-device-private.h b/src/fu-device-private.h
index f75a5bad7..0b928630a 100644
--- a/src/fu-device-private.h
+++ b/src/fu-device-private.h
@@ -26,7 +26,6 @@
 
 G_BEGIN_DECLS
 
-gchar		*fu_device_to_string			(FuDevice	*device);
 const gchar	*fu_device_get_version_new		(FuDevice	*device);
 void		 fu_device_set_version_new		(FuDevice	*device,
 							 const gchar	*version_new);
diff --git a/src/fu-device.c b/src/fu-device.c
index 0813e9019..80fc9b324 100644
--- a/src/fu-device.c
+++ b/src/fu-device.c
@@ -626,6 +626,7 @@ fu_device_set_progress (FuDevice *device, guint progress)
 gchar *
 fu_device_to_string (FuDevice *device)
 {
+	FuDeviceClass *klass = FU_DEVICE_GET_CLASS (device);
 	FuDevicePrivate *priv = GET_PRIVATE (device);
 	GString *str = g_string_new ("");
 	g_autofree gchar *tmp = NULL;
@@ -648,6 +649,11 @@ fu_device_to_string (FuDevice *device)
 		const gchar *value = g_hash_table_lookup (priv->metadata, key);
 		fwupd_pad_kv_str (str, key, value);
 	}
+
+	/* subclassed */
+	if (klass->to_string != NULL)
+		klass->to_string (device, str);
+
 	return g_string_free (str, FALSE);
 }
 
diff --git a/src/fu-device.h b/src/fu-device.h
index 18b21b51c..9f8416257 100644
--- a/src/fu-device.h
+++ b/src/fu-device.h
@@ -33,6 +33,8 @@ G_DECLARE_DERIVABLE_TYPE (FuDevice, fu_device, FU, DEVICE, FwupdDevice)
 struct _FuDeviceClass
 {
 	FwupdDeviceClass	 parent_class;
+	void			 (*to_string)		(FuDevice	*device,
+							 GString	*str);
 };
 
 /**
@@ -94,6 +96,7 @@ FuDevice	*fu_device_new				(void);
 #define fu_device_get_flashes_left(d)		fwupd_device_get_flashes_left(FWUPD_DEVICE(d))
 
 /* accessors */
+gchar		*fu_device_to_string			(FuDevice	*device);
 const gchar	*fu_device_get_equivalent_id		(FuDevice	*device);
 void		 fu_device_set_equivalent_id		(FuDevice	*device,
 							 const gchar	*equivalent_id);