diff --git a/patches/minecraft/net/minecraft/inventory/container/RepairContainer.java.patch b/patches/minecraft/net/minecraft/inventory/container/RepairContainer.java.patch
index 3bdf12fae..f80b84bf2 100644
--- a/patches/minecraft/net/minecraft/inventory/container/RepairContainer.java.patch
+++ b/patches/minecraft/net/minecraft/inventory/container/RepairContainer.java.patch
@@ -26,7 +26,7 @@
 +
           if (!itemstack2.func_190926_b()) {
 -            boolean flag = itemstack2.func_77973_b() == Items.field_151134_bR && !EnchantedBookItem.func_92110_g(itemstack2).isEmpty();
-+            if (!net.minecraftforge.common.ForgeHooks.onAnvilChange(this, itemstack, itemstack2, field_234642_c_, field_82857_m, j)) return;
++            if (!net.minecraftforge.common.ForgeHooks.onAnvilChange(this, itemstack, itemstack2, field_234642_c_, field_82857_m, j, this.field_234645_f_)) return;
 +            flag = itemstack2.func_77973_b() == Items.field_151134_bR && !EnchantedBookItem.func_92110_g(itemstack2).isEmpty();
              if (itemstack1.func_77984_f() && itemstack1.func_77973_b().func_82789_a(itemstack, itemstack2)) {
                 int l2 = Math.min(itemstack1.func_77952_i(), itemstack1.func_77958_k() / 4);
diff --git a/src/main/java/net/minecraftforge/common/ForgeHooks.java b/src/main/java/net/minecraftforge/common/ForgeHooks.java
index de5d481cb..e934f49df 100644
--- a/src/main/java/net/minecraftforge/common/ForgeHooks.java
+++ b/src/main/java/net/minecraftforge/common/ForgeHooks.java
@@ -672,9 +672,15 @@ public class ForgeHooks
         return ret;
     }
 
+    @Deprecated // TODO: Remove 1.17 - Use player-contextual version below.
     public static boolean onAnvilChange(RepairContainer container, @Nonnull ItemStack left, @Nonnull ItemStack right, IInventory outputSlot, String name, int baseCost)
     {
-        AnvilUpdateEvent e = new AnvilUpdateEvent(left, right, name, baseCost);
+        return onAnvilChange(container, left, right, outputSlot, name, baseCost, null);
+    }
+
+    public static boolean onAnvilChange(RepairContainer container, @Nonnull ItemStack left, @Nonnull ItemStack right, IInventory outputSlot, String name, int baseCost, PlayerEntity player)
+    {
+        AnvilUpdateEvent e = new AnvilUpdateEvent(left, right, name, baseCost, player);
         if (MinecraftForge.EVENT_BUS.post(e)) return false;
         if (e.getOutput().isEmpty()) return true;
 
diff --git a/src/main/java/net/minecraftforge/event/AnvilUpdateEvent.java b/src/main/java/net/minecraftforge/event/AnvilUpdateEvent.java
index a80faef46..a19c7638e 100644
--- a/src/main/java/net/minecraftforge/event/AnvilUpdateEvent.java
+++ b/src/main/java/net/minecraftforge/event/AnvilUpdateEvent.java
@@ -19,52 +19,150 @@
 
 package net.minecraftforge.event;
 
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.inventory.container.RepairContainer;
+import net.minecraft.item.ItemStack;
 import net.minecraftforge.eventbus.api.Cancelable;
 import net.minecraftforge.eventbus.api.Event;
-import net.minecraft.item.ItemStack;
 
-import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * 
- * AnvilUpdateEvent is fired when a player places items in both the left and right slots of a anvil.
- * If the event is canceled, vanilla behavior will not run, and the output will be set to null.
- * If the event is not canceled, but the output is not null, it will set the output and not run vanilla behavior.
- * if the output is null, and the event is not canceled, vanilla behavior will execute.
+ * AnvilUpdateEvent is fired when the inputs (either input stack, or the name) to an anvil are changed. <br> 
+ * It is called from {@link RepairContainer#updateRepairOutput}. <br>
+ * If the event is canceled, vanilla behavior will not run, and the output will be set to {@link ItemStack#EMPTY}. <br>
+ * If the event is not canceled, but the output is not empty, it will set the output and not run vanilla behavior. <br>
+ * if the output is empty, and the event is not canceled, vanilla behavior will execute. <br>
  */
 @Cancelable
 public class AnvilUpdateEvent extends Event
 {
-    @Nonnull
-    private final ItemStack left;  // The left side of the input
-    @Nonnull
-    private final ItemStack right; // The right side of the input
-    private final String name;     // The name to set the item, if the user specified one.
-    @Nonnull
-    private ItemStack output;      // Set this to set the output stack
-    private int cost;              // The base cost, set this to change it if output != null
-    private int materialCost; // The number of items from the right slot to be consumed during the repair. Leave as 0 to consume the entire stack.
 
-    public AnvilUpdateEvent(@Nonnull ItemStack left, @Nonnull ItemStack right, String name, int cost)
+    private final ItemStack left;
+    private final ItemStack right;
+    private final String name;
+    private ItemStack output;
+    private int cost;
+    private int materialCost;
+    @Nullable // TODO: Remove 1.17 - Nullable only in the instance that a mod uses the deprecated ctor.
+    private final PlayerEntity player;
+
+    @Deprecated //TODO: Remove 1.17 - Use Player-contextual constructor below.
+    public AnvilUpdateEvent(ItemStack left, ItemStack right, String name, int cost)
+    {
+        this(left, right, name, cost, null);
+    }
+
+    public AnvilUpdateEvent(ItemStack left, ItemStack right, String name, int cost, PlayerEntity player)
     {
         this.left = left;
         this.right = right;
         this.output = ItemStack.EMPTY;
         this.name = name;
+        this.player = player;
         this.setCost(cost);
         this.setMaterialCost(0);
     }
 
-    @Nonnull
-    public ItemStack getLeft() { return left; }
-    @Nonnull
-    public ItemStack getRight() { return right; }
-    public String getName() { return name; }
-    @Nonnull
-    public ItemStack getOutput() { return output; }
-    public void setOutput(@Nonnull ItemStack output) { this.output = output; }
-    public int getCost() { return cost; }
-    public void setCost(int cost) { this.cost = cost; }
-    public int getMaterialCost() { return materialCost; }
-    public void setMaterialCost(int materialCost) { this.materialCost = materialCost; }
+    /**
+     * @return The item in the left input (leftmost) anvil slot.
+     */
+    public ItemStack getLeft()
+    {
+        return left;
+    }
+
+    /**
+     * @return The item in the right input (center) anvil slot.
+     */
+    public ItemStack getRight()
+    {
+        return right;
+    }
+
+    /**
+     * This is the name as sent by the client.  It may be null if none has been sent. <br>
+     * If empty, it indicates the user wishes to clear the custom name from the item.
+     * @return The name that the output item will be set to, if applicable.
+     */
+    @Nullable
+    public String getName()
+    {
+        return name;
+    }
+
+    /**
+     * This is the output as determined by the event, not by the vanilla behavior between these two items. <br>
+     * If you are the first receiver of this event, it is guaranteed to be empty. <br>
+     * It will only be non-empty if changed by an event handler. <br>
+     * If this event is cancelled, this output stack is discarded.
+     * @return The item to set in the output (rightmost) anvil slot.
+     */
+    public ItemStack getOutput() 
+    {
+        return output;
+    }
+
+    /**
+     * Sets the output slot to a specific itemstack.
+     * @param output The stack to change the output to.
+     */
+    public void setOutput(ItemStack output)
+    {
+        this.output = output;
+    }
+
+    /**
+     * This is the level cost of this anvil operation. <br> 
+     * When unchanged, it is guaranteed to be left.getRepairCost() + right.getRepairCost().
+     * @return The level cost of this anvil operation.
+     */
+    public int getCost()
+    {
+        return cost;
+    }
+
+    /**
+     * Changes the level cost of this operation. <br>
+     * The level cost does prevent the output from being available.  <br>
+     * That is, a player without enough experience may not take the output.
+     * @param cost The new level cost.
+     */
+    public void setCost(int cost)
+    {
+        this.cost = cost;
+    }
+
+    /**
+     * The material cost is how many units of the right input stack are consumed.
+     * @return The material cost of this anvil operation.
+     */
+    public int getMaterialCost()
+    {
+        return materialCost;
+    }
+
+    /**
+     * Sets how many right inputs are consumed. <br>
+     * A material cost of zero consumes the entire stack. <br>
+     * A material cost higher than the count of the right stack
+     * consumes the entire stack. <br>
+     * The material cost does not prevent the output from being available.
+     * @param materialCost The new material cost.
+     */
+    public void setMaterialCost(int materialCost)
+    {
+        this.materialCost = materialCost;
+    }
+
+    /**
+     * Nullable in the case someone is using the deprecated constructor.
+     * @return The player using this anvil container.
+     */
+    @Nullable // TODO: Remove 1.17
+    public PlayerEntity getPlayer()
+    {
+        return this.player;
+    }
 }