diff --git a/inventoryManager.lua b/inventoryManager.lua
index 5946818..3d71c5a 100644
--- a/inventoryManager.lua
+++ b/inventoryManager.lua
@@ -673,6 +673,14 @@ local function main()
 
                     if isCommandDuplicate(message.commandId) then
                         log.debug("NET", "Duplicate command skipped: %s", tostring(message.commandId))
+                        -- Still ACK so the sender stops retrying
+                        pcall(function()
+                            ctx.networkModem.transmit(replyChannel, cfg.ORDER_CHANNEL, {
+                                type      = "command_ack",
+                                commandId = message.commandId,
+                                success   = true,
+                            })
+                        end)
                     else
                         recordCommandId(message.commandId)
                         cleanupCommandIds()