diff --git a/src/test/java/net/minestom/server/inventory/PlayerSlotConversionTest.java b/src/test/java/net/minestom/server/inventory/PlayerSlotConversionTest.java
new file mode 100644
index 000000000..bbbb5e776
--- /dev/null
+++ b/src/test/java/net/minestom/server/inventory/PlayerSlotConversionTest.java
@@ -0,0 +1,60 @@
+package net.minestom.server.inventory;
+
+import org.junit.jupiter.api.Test;
+
+import static net.minestom.server.utils.inventory.PlayerInventoryUtils.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Test conversion between packet slots & internal ones (used in events and inventory methods)
+ */
+public class PlayerSlotConversionTest {
+
+    @Test
+    public void hotbar() {
+        // Convert 36-44 into 0-8
+        for (int i = 0; i < 9; i++) {
+            assertEquals(i, convertPlayerInventorySlot(i + 36, OFFSET));
+        }
+    }
+
+    @Test
+    public void mainInventory() {
+        // No conversion, slots should stay 9-35
+        for (int i = 9; i < 9 * 4; i++) {
+            assertEquals(i, convertPlayerInventorySlot(i, OFFSET));
+        }
+    }
+
+    @Test
+    public void armor() {
+        assertEquals(HELMET_SLOT, 41);
+        assertEquals(CHESTPLATE_SLOT, 42);
+        assertEquals(LEGGINGS_SLOT, 43);
+        assertEquals(BOOTS_SLOT, 44);
+        assertEquals(OFFHAND_SLOT, 45);
+
+        // Convert 5-8 & 45 into 41-45
+        assertEquals(HELMET_SLOT, convertPlayerInventorySlot(5, OFFSET));
+        assertEquals(CHESTPLATE_SLOT, convertPlayerInventorySlot(6, OFFSET));
+        assertEquals(LEGGINGS_SLOT, convertPlayerInventorySlot(7, OFFSET));
+        assertEquals(BOOTS_SLOT, convertPlayerInventorySlot(8, OFFSET));
+        assertEquals(OFFHAND_SLOT, convertPlayerInventorySlot(45, OFFSET));
+    }
+
+    @Test
+    public void craft() {
+        assertEquals(CRAFT_RESULT, 36);
+        assertEquals(CRAFT_SLOT_1, 37);
+        assertEquals(CRAFT_SLOT_2, 38);
+        assertEquals(CRAFT_SLOT_3, 39);
+        assertEquals(CRAFT_SLOT_4, 40);
+
+        // Convert 0-4 into 36-40
+        assertEquals(CRAFT_RESULT, convertPlayerInventorySlot(0, OFFSET));
+        assertEquals(CRAFT_SLOT_1, convertPlayerInventorySlot(1, OFFSET));
+        assertEquals(CRAFT_SLOT_2, convertPlayerInventorySlot(2, OFFSET));
+        assertEquals(CRAFT_SLOT_3, convertPlayerInventorySlot(3, OFFSET));
+        assertEquals(CRAFT_SLOT_4, convertPlayerInventorySlot(4, OFFSET));
+    }
+}