diff --git a/swift/Sources/GildedRose/ItemQualityUpdater.swift b/swift/Sources/GildedRose/ItemQualityUpdater.swift
index 305ac4b6..3712e775 100644
--- a/swift/Sources/GildedRose/ItemQualityUpdater.swift
+++ b/swift/Sources/GildedRose/ItemQualityUpdater.swift
@@ -8,6 +8,9 @@
 import Foundation
 
 protocol ItemQualityUpdater: CustomisedItem {
+    func reduceItemQuality(by value:Int)
+    func increaseItemQuality(by value:Int)
+    func setItemQuality(to value: Int)
 }
 
 extension ItemQualityUpdater {
diff --git a/swift/Sources/GildedRose/Items/AgedBrieItem.swift b/swift/Sources/GildedRose/Items/AgedBrieItem.swift
index d8a4ba8c..c7127bfd 100644
--- a/swift/Sources/GildedRose/Items/AgedBrieItem.swift
+++ b/swift/Sources/GildedRose/Items/AgedBrieItem.swift
@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct AgedBrieItem: ItemStateUpdater{
+struct AgedBrieItem: CustomisedItem, ItemStateUpdater{
     var item: Item
     
     private var isItemUnderHighestQuality: Bool {
@@ -20,7 +20,7 @@ struct AgedBrieItem: ItemStateUpdater{
     
     func updateItemState() {
         // update the sell in days. Reduce the Sell In days by 1
-        reduceSellInDays(by: 1)
+        self.reduceSellInDays(by: 1)
         
         // Increment the Item quality by 1 if the quality is less than 50
         guard isItemUnderHighestQuality else { return }
diff --git a/swift/Sources/GildedRose/Items/BackstagePassesItem.swift b/swift/Sources/GildedRose/Items/BackstagePassesItem.swift
index c33ce1f0..2fd0b752 100644
--- a/swift/Sources/GildedRose/Items/BackstagePassesItem.swift
+++ b/swift/Sources/GildedRose/Items/BackstagePassesItem.swift
@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct BackstagePassesItem: ItemStateUpdater {
+struct BackstagePassesItem: CustomisedItem, ItemStateUpdater {
     var item: Item
     
     private var isItemUnderHighestQuality: Bool {
diff --git a/swift/Sources/GildedRose/Items/StandardItem.swift b/swift/Sources/GildedRose/Items/StandardItem.swift
index dea032f7..93ecb58f 100644
--- a/swift/Sources/GildedRose/Items/StandardItem.swift
+++ b/swift/Sources/GildedRose/Items/StandardItem.swift
@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct StandardItem: ItemStateUpdater {
+struct StandardItem: CustomisedItem, ItemStateUpdater {
     var item: Item
     
     private var isSellInDatePassed: Bool{