diff --git a/rc/theme.lua b/rc/theme.lua
index f4a0c51..ff6d24a 100644
--- a/rc/theme.lua
+++ b/rc/theme.lua
@@ -65,7 +65,7 @@ for _, preset in pairs({"normal", "low", "critical"}) do
    naughty.config.presets[preset].border_width = 3 * theme.scale
 end
 naughty.config.notify_callback = function(args)
-   if args.icon ~= nil and string.sub(args.icon, 1, 5) ~= "/usr/" then
+   if args.icon ~= nil and type(args.icon) ~= "string" then
       args.icon = nil
    end
    return args