diff --git a/lib/plugins/inventory.js b/lib/plugins/inventory.js
index f4ef1d00d..291d6dcf1 100644
--- a/lib/plugins/inventory.js
+++ b/lib/plugins/inventory.js
@@ -549,6 +549,10 @@ function inject (bot, { hideErrors }) {
     return changedSlots
   }
 
+  // 1.21.5+ clicks claim slot contents by hash; the server resends any slot
+  // whose claim doesn't match its own state.
+  const toClickNotch = bot.registry.protocol.types.HashedSlot ? Item.toHashedNotch : Item.toNotch
+
   async function clickWindow (slot, mouseButton, mode) {
     // if you click on the quick bar and have dug recently,
     // wait a bit
@@ -600,7 +604,7 @@ function inject (bot, { hideErrors }) {
       changedSlots = changedSlots.map(slot => {
         return {
           location: slot,
-          item: Item.toNotch(window.slots[slot])
+          item: toClickNotch(window.slots[slot])
         }
       })
     }
@@ -614,7 +618,7 @@ function inject (bot, { hideErrors }) {
         mouseButton,
         mode,
         changedSlots,
-        cursorItem: Item.toNotch(window.selectedItem)
+        cursorItem: toClickNotch(window.selectedItem)
       })
     } else if (bot.supportFeature('actionIdUsed')) { // <= 1.16.5
       bot._client.write('window_click', {
@@ -834,7 +838,7 @@ function inject (bot, { hideErrors }) {
       mouseButton: 2, // end of a drag that never started
       mode: 5,
       changedSlots: [],
-      cursorItem: Item.toNotch(window.selectedItem)
+      cursorItem: toClickNotch(window.selectedItem)
     })
     await synced
   }