diff --git a/libfwupdplugin/fu-device.c b/libfwupdplugin/fu-device.c
index 42fb65dc7..03e626b16 100644
--- a/libfwupdplugin/fu-device.c
+++ b/libfwupdplugin/fu-device.c
@@ -3147,24 +3147,17 @@ fu_device_rescan (FuDevice *self, GError **error)
 void
 fu_device_convert_instance_ids (FuDevice *self)
 {
-	GPtrArray *children;
-	GPtrArray *instance_ids = fwupd_device_get_instance_ids (FWUPD_DEVICE (self));
+	GPtrArray *instance_ids;
 
 	/* OEM specific hardware */
 	if (fu_device_has_internal_flag (self, FU_DEVICE_INTERNAL_FLAG_NO_AUTO_INSTANCE_IDS))
 		return;
+	instance_ids = fwupd_device_get_instance_ids (FWUPD_DEVICE (self));
 	for (guint i = 0; i < instance_ids->len; i++) {
 		const gchar *instance_id = g_ptr_array_index (instance_ids, i);
 		g_autofree gchar *guid = fwupd_guid_hash_string (instance_id);
 		fwupd_device_add_guid (FWUPD_DEVICE (self), guid);
 	}
-
-	/* convert all children too */
-	children = fu_device_get_children (self);
-	for (guint i = 0; i < children->len; i++) {
-		FuDevice *devtmp = g_ptr_array_index (children, i);
-		fu_device_convert_instance_ids (devtmp);
-	}
 }
 
 /**
@@ -3185,6 +3178,7 @@ fu_device_setup (FuDevice *self, GError **error)
 {
 	FuDevicePrivate *priv = GET_PRIVATE (self);
 	FuDeviceClass *klass = FU_DEVICE_GET_CLASS (self);
+	GPtrArray *children;
 
 	g_return_val_if_fail (FU_IS_DEVICE (self), FALSE);
 	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
@@ -3199,6 +3193,14 @@ fu_device_setup (FuDevice *self, GError **error)
 			return FALSE;
 	}
 
+	/* run setup on the children too (unless done already) */
+	children = fu_device_get_children (self);
+	for (guint i = 0; i < children->len; i++) {
+		FuDevice *child_tmp = g_ptr_array_index (children, i);
+		if (!fu_device_setup (child_tmp, error))
+			return FALSE;
+	}
+
 	/* convert the instance IDs to GUIDs */
 	fu_device_convert_instance_ids (self);
 
diff --git a/libfwupdplugin/fu-self-test.c b/libfwupdplugin/fu-self-test.c
index 7db4848b0..b8e7b8cec 100644
--- a/libfwupdplugin/fu-self-test.c
+++ b/libfwupdplugin/fu-self-test.c
@@ -1180,6 +1180,33 @@ fu_device_flags_func (void)
 	g_assert_cmpint (fu_device_get_flags (device), ==, FWUPD_DEVICE_FLAG_UPDATABLE);
 }
 
+static void
+fu_device_children_func (void)
+{
+	gboolean ret;
+	g_autoptr(FuDevice) child = fu_device_new ();
+	g_autoptr(FuDevice) parent = fu_device_new ();
+	g_autoptr(GError) error = NULL;
+
+	fu_device_set_physical_id (child, "dummy");
+	fu_device_set_physical_id (parent, "dummy");
+
+	/* set up family */
+	fu_device_add_child (parent, child);
+
+	/* set an instance ID that will be converted to a GUID when the parent
+	 * calls ->setup */
+	fu_device_add_instance_id (child, "foo");
+	g_assert_false (fu_device_has_guid (child, "b84ed8ed-a7b1-502f-83f6-90132e68adef"));
+
+	/* setup parent, which also calls setup on child too (and thus also
+	 * converts the instance ID to a GUID) */
+	ret = fu_device_setup (parent, &error);
+	g_assert_no_error (error);
+	g_assert_true (ret);
+	g_assert_true (fu_device_has_guid (child, "b84ed8ed-a7b1-502f-83f6-90132e68adef"));
+}
+
 static void
 fu_device_parent_func (void)
 {
@@ -2249,6 +2276,7 @@ main (int argc, char **argv)
 	g_test_add_func ("/fwupd/device{instance-ids}", fu_device_instance_ids_func);
 	g_test_add_func ("/fwupd/device{flags}", fu_device_flags_func);
 	g_test_add_func ("/fwupd/device{parent}", fu_device_parent_func);
+	g_test_add_func ("/fwupd/device{children}", fu_device_children_func);
 	g_test_add_func ("/fwupd/device{incorporate}", fu_device_incorporate_func);
 	if (g_test_slow ())
 		g_test_add_func ("/fwupd/device{poll}", fu_device_poll_func);