diff --git a/system/on_receive_fields.lua b/system/on_receive_fields.lua
index 0f26aaa..aa853b5 100644
--- a/system/on_receive_fields.lua
+++ b/system/on_receive_fields.lua
@@ -135,7 +135,8 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
     -- Set size (scaling) of the timer HUD element
     if formname == 'mtimer:hud_element_size' then
         local attr = m.meta.hud_element_size
-        local value = tonumber(fields.hud_element_size or attr.default)
+        local default = tonumber(attr.default)
+        local value = tonumber(fields.hud_element_size) or default
 
         if fields.add then value = value + 1 end
         if fields.substract then value = value - 1 end