diff --git a/plugins/player_sync/module/get_script_data.lua b/plugins/player_sync/module/get_script_data.lua
index 52f207b7..7a1dbf8b 100644
--- a/plugins/player_sync/module/get_script_data.lua
+++ b/plugins/player_sync/module/get_script_data.lua
@@ -18,6 +18,7 @@ return function(no_early_return)
 	player_sync.players_waiting_for_acquire = player_sync.players_waiting_for_acquire or {}
 	player_sync.players_in_cutscene_to_sync = player_sync.players_in_cutscene_to_sync or {}
 	player_sync.failed_deserialization = player_sync.failed_deserialization or {}
+	player_sync.inventory_bonus_raises = player_sync.inventory_bonus_raises or {}
 
 	player_sync.active_downloads = player_sync.active_downloads or {}
 	player_sync.finished_downloads = player_sync.finished_downloads or {}
diff --git a/plugins/player_sync/module/player_sync.lua b/plugins/player_sync/module/player_sync.lua
index 6285c8fe..1569ae9f 100644
--- a/plugins/player_sync/module/player_sync.lua
+++ b/plugins/player_sync/module/player_sync.lua
@@ -60,6 +60,19 @@ local function remove_player(player)
 	script_data.players[player.name] = nil
 end
 
+-- Remove the temporary inventory bonus a deserialized character got to fit its main inventory
+local function remove_inventory_bonus_raise(script_data, player_name)
+	local raises = script_data.inventory_bonus_raises
+	local raise = raises and raises[player_name]
+	if raise then
+		raises[player_name] = nil
+		local character = raise.character
+		if character.valid then
+			character.character_inventory_slots_bonus = character.character_inventory_slots_bonus - raise.bonus
+		end
+	end
+end
+
 
 player_sync = {}
 -- This function is called by instance.js as /sc player_sync.download_inventory("danielv", Escaped JSON string, package_number, total_packages_count) with data from the controller
@@ -100,6 +113,15 @@ function player_sync.serialize_player(player, player_record)
 	local serialized_player = serialize.serialize_player(player, failed_deserialization, player_record.components)
 	serialized_player.generation = player_record.generation
 
+	-- Leaving on the tick of a download the temporary bonus is still there and must not be uploaded. Removing it
+	-- from the character here would shrink the main inventory before the armor's bonus applies and spill items.
+	local raises = get_script_data().inventory_bonus_raises
+	local raise = raises and raises[player.name]
+	local character = serialized_player.character
+	if raise and character and raise.character == player.character then
+		character.character_inventory_slots_bonus = character.character_inventory_slots_bonus - raise.bonus
+	end
+
 	return serialized_player
 end
 
@@ -134,10 +156,18 @@ function player_sync.deserialize_player(player, finished_record)
 	-- Deserialize downloaded player data
 	local serialized_player = compat.json_to_table(finished_record.data)
 	assert(type(serialized_player) == "table", "wrong type for serialized_player")
-	local failed, spill =
+	-- An earlier raise not removed yet is replaced, the character's inventory bonus is restored with the data
+	script_data.inventory_bonus_raises[player.name] = nil
+	local failed, spill, inventory_bonus_raise =
 		serialize.deserialize_player(player, serialized_player, finished_record.components, local_controller)
 	script_data.failed_deserialization[player.name] = failed
 	player_record.local_controller = nil
+	if inventory_bonus_raise and inventory_bonus_raise > 0 then
+		script_data.inventory_bonus_raises[player.name] = {
+			character = player.character,
+			bonus = inventory_bonus_raise,
+		}
+	end
 
 	-- Restore player position and driving state
 	restore_position(player, finished_record)
@@ -396,6 +426,12 @@ player_sync.events[defines.events.on_player_joined_game] = function(event)
 	script_data.active_uploads[player.name] = nil
 end
 
+-- Raised for a restored armor after its equipment's inventory bonus applied, the temporary bonus is no longer needed
+player_sync.events[defines.events.on_player_armor_inventory_changed] = function(event)
+	local player = assert(game.get_player(event.player_index))
+	remove_inventory_bonus_raise(get_script_data(), player.name)
+end
+
 player_sync.on_nth_tick = {}
 player_sync.on_nth_tick[33] = function(event)
 	-- Periodically check players currently in the process of syncing
diff --git a/plugins/player_sync/module/serialize.lua b/plugins/player_sync/module/serialize.lua
index 7f9b3b2a..368766a6 100644
--- a/plugins/player_sync/module/serialize.lua
+++ b/plugins/player_sync/module/serialize.lua
@@ -10,6 +10,7 @@ local v2_storage_api = compat.version_ge("2.0.0")
 local v2_remote_controller = compat.version_ge("2.0.0")
 local v2_space_platform = compat.version_ge("2.0.0")
 local v2_exit_remote_view = compat.version_ge("2.0.56")
+local v2_inventory_bonus_equipment = compat.version_ge("2.0.0")
 local recipe_notifications_api = compat.version_ge("2.0.67")
 local v2_0_quick_bar_api = compat.version_ge("2.0.0")
 local v2_1_quick_bar_api = compat.version_ge("2.1.0")
@@ -73,6 +74,30 @@ function serialize.deserialize_character(character, serialized)
 	end
 end
 
+--- Index of the last slot used by a serialized inventory
+local function last_slot_index(serialized)
+	local last = 0
+	for _, entry in ipairs(serialized.i) do
+		last = (entry.s or last + 1) + (entry.r or 0)
+	end
+	return last
+end
+
+--- Raise the inventory bonus of a character with its armor restored by the bonus of the armor's equipment which is
+--- still to come, as far as a serialized main inventory needs it
+--- @return integer raise Slots added to character_inventory_slots_bonus, removed again once the armor's bonus applies
+local function raise_inventory_bonus(character, main)
+	local grid = character.grid --[[@as LuaEquipmentGrid]]
+	local equipment_bonus = 0
+	for _, equipment in pairs(grid.equipment) do
+		equipment_bonus = equipment_bonus + equipment.inventory_bonus
+	end
+	local delayed = equipment_bonus - grid.inventory_bonus
+	local raise = math.max(0, math.min(last_slot_index(main) - #character.get_main_inventory(), delayed))
+	character.character_inventory_slots_bonus = character.character_inventory_slots_bonus + raise
+	return raise
+end
+
 --- Restore the armor grid state, the grid exists after the armor inventory is restored
 function serialize.deserialize_character_grid(character, serialized)
 	local grid = character.grid
@@ -190,15 +215,18 @@ end
 --- @param destinations table<string, LuaInventory>
 --- @param inventories table<string, table>?
 --- @param items { name: string, count: integer, quality: string? }[]?
+--- @param after_armor fun()? Called once the armor is restored, before the other inventories
 --- @return table[] leftovers
-function serialize.place_items(destinations, inventories, items)
+function serialize.place_items(destinations, inventories, items, after_armor)
 	for _, destination in pairs(destinations) do
 		destination.clear()
 	end
 
-	-- Every inventory is restored before inserting into them, as restoring a slot replaces what is in it
+	-- Every inventory is restored before inserting into them, as restoring a slot replaces what is in it.
+	-- The armor first, its inventory bonus changes the size of the main inventory.
+	inventories = inventories or {}
 	local pending = {}
-	for name, serialized in pairs(inventories or {}) do
+	local function restore(name, serialized)
 		local destination = destinations[name]
 		local fitting, rest = split_inventory(serialized, destination and #destination or 0)
 		if destination then
@@ -208,6 +236,17 @@ function serialize.place_items(destinations, inventories, items)
 			table.insert(pending, { from = destination, stack = stack })
 		end
 	end
+	if inventories.armor then
+		restore("armor", inventories.armor)
+	end
+	if after_armor then
+		after_armor()
+	end
+	for name, serialized in pairs(inventories) do
+		if name ~= "armor" then
+			restore(name, serialized)
+		end
+	end
 	for _, item in pairs(items or {}) do
 		table.insert(pending, { stack = { n = item.name, c = item.count, q = item.quality } })
 	end
@@ -1226,6 +1265,7 @@ end
 --- @param components SyncComponents
 --- @param local_controller LocalControllerState? Controller to restore when the controller is not synced
 --- @return FailedDeserializationPlayerData?, table[]? Serialized stacks which did not fit, see spill_items
+--- @return integer? inventory_bonus_raise See raise_inventory_bonus
 function serialize.deserialize_player(player, serialized, components, local_controller)
 	local failed_deserialization = {}
 	local sync_controller = syncs(components, "controller")
@@ -1347,14 +1387,24 @@ function serialize.deserialize_player(player, serialized, components, local_cont
 
 	-- Deserialize items, a ghost got them while it had a character above
 	local character = player.character
+	local inventory_bonus_raise
 	if place and not to_ghost then
 		local stats = character and items.character
 		if stats then
 			serialize.deserialize_character(character, stats)
 		end
 		local craft = character and queue
+		-- The bonus of the armor's equipment (toolbelts) only applies at the end of the tick, so once the armor is
+		-- restored the main inventory is raised by the part of that bonus still to come. Slots past it overflow and
+		-- are left over as without the raise. Only for armor with a grid, restoring it raises
+		-- on_player_armor_inventory_changed which removes the raise.
 		spill = serialize.place_items(
-			serialize.item_destinations(player), inventories, not craft and queue and queue.ingredients or nil
+			serialize.item_destinations(player), inventories, not craft and queue and queue.ingredients or nil,
+			function()
+				if v2_inventory_bonus_equipment and stats and inventories.main and character and character.grid then
+					inventory_bonus_raise = raise_inventory_bonus(character, inventories.main)
+				end
+			end
 		)
 		if stats then
 			serialize.deserialize_character_grid(character, stats)
@@ -1378,7 +1428,7 @@ function serialize.deserialize_player(player, serialized, components, local_cont
 			serialize.deserialize_crafting_notifications(player, serialized.recipe_notifications)
 	end
 
-	return next(failed_deserialization) and failed_deserialization or nil, spill
+	return next(failed_deserialization) and failed_deserialization or nil, spill, inventory_bonus_raise
 end
 
 return serialize