diff -up libappindicator-12.10.0/src/app-indicator.c.build_fix libappindicator-12.10.0/src/app-indicator.c

--- libappindicator-12.10.0/src/app-indicator.c.build_fix	2018-04-10 14:43:57.134400594 +0200

+++ libappindicator-12.10.0/src/app-indicator.c	2018-04-10 14:45:34.655448722 +0200

@@ -2196,7 +2196,7 @@ app_indicator_set_secondary_activate_tar

 	g_return_if_fail (GTK_IS_WIDGET (menuitem));

-	priv->sec_activate_target = g_object_ref(G_OBJECT(menuitem));

+	priv->sec_activate_target = g_object_ref(menuitem);

 	priv->sec_activate_enabled = widget_is_menu_child(self, menuitem);

 	g_signal_connect(menuitem, "parent-set", G_CALLBACK(sec_activate_target_parent_changed), self);

 }