diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index 45e14cfb45..3cacae4305 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -1273,7 +1273,7 @@ public class CraftEventFactory {
     }
 
     public static ItemStack handleEditBookEvent(EntityPlayer player, int itemInHandIndex, ItemStack itemInHand, ItemStack newBookItem) {
-        PlayerEditBookEvent editBookEvent = new PlayerEditBookEvent(player.getBukkitEntity(), itemInHandIndex, (BookMeta) CraftItemStack.getItemMeta(itemInHand), (BookMeta) CraftItemStack.getItemMeta(newBookItem), newBookItem.getItem() == Items.WRITTEN_BOOK);
+        PlayerEditBookEvent editBookEvent = new PlayerEditBookEvent(player.getBukkitEntity(), (itemInHandIndex >= 0 && itemInHandIndex <= 8) ? itemInHandIndex : -1, (BookMeta) CraftItemStack.getItemMeta(itemInHand), (BookMeta) CraftItemStack.getItemMeta(newBookItem), newBookItem.getItem() == Items.WRITTEN_BOOK);
         player.world.getServer().getPluginManager().callEvent(editBookEvent);
 
         // If they've got the same item in their hand, it'll need to be updated.