diff --git a/libs/turtle-utils.lua b/libs/turtle-utils.lua
index e247b3a..2af9561 100644
--- a/libs/turtle-utils.lua
+++ b/libs/turtle-utils.lua
@@ -252,8 +252,9 @@ local function compactItem(itemName)
   end
 end
 
--- Compact the internal turtle inventory
+-- Compact the internal turtle inventory (return the number of freed slots)
 turtleUtils.compactInventory = function()
+  local initialNbFreeSlots = turtle.countFreeSlots()
   local initialSelectedSlot = turtle.getSelectedSlot()
   local itemsMap = getItemsMap()
 
@@ -266,6 +267,8 @@ turtleUtils.compactInventory = function()
   if initialSelectedSlot ~= turtle.getSelectedSlot() then
     turtle.select(initialSelectedSlot)
   end
+
+  return turtle.countFreeSlots() - initialNbFreeSlots
 end
 
 return turtleUtils
\ No newline at end of file