diff --git a/bags.lua b/bags.lua
index 497a9f8..2a21d5d 100644
--- a/bags.lua
+++ b/bags.lua
@@ -48,6 +48,9 @@ for i = 1, 4 do
 end
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if formname ~= "" then
+		return
+	end
 	for i = 1, 4 do
 		if fields["bag"..i] then
 			local stack = player:get_inventory():get_stack("bag"..i, 1)
diff --git a/callbacks.lua b/callbacks.lua
index 53601b0..fe76543 100644
--- a/callbacks.lua
+++ b/callbacks.lua
@@ -49,6 +49,9 @@ minetest.register_on_joinplayer(function(player)
 end)
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if formname ~= "" then
+		return
+	end
 	local player_name = player:get_player_name()
 
 	for i, def in pairs(unified_inventory.buttons) do