diff --git a/python/gilded_rose.py b/python/gilded_rose.py
index 9a1f48e2..a1fe25e0 100755
--- a/python/gilded_rose.py
+++ b/python/gilded_rose.py
@@ -33,6 +33,32 @@ class GildedRose:
         """
         self.items = items
 
+    def _increase_quality(self, item: Item, amount: int = 1) -> None:
+        """Increase the quality of an item, ensuring it does not exceed MAX_QUALITY.
+
+        Parameters
+        ----------
+        item : Item
+            The item whose quality is to be increased.
+        amount : int, optional
+            The amount to increase the quality by (default is 1).
+
+        """
+        item.quality = min(MAX_QUALITY, item.quality + amount)
+
+    def _decrease_quality(self, item: Item, amount: int = 1) -> None:
+        """Decrease the quality of an item, ensuring it does not go below MIN_QUALITY.
+
+        Parameters
+        ----------
+        item : Item
+            The item whose quality is to be decreased.
+        amount : int, optional
+            The amount to decrease the quality by (default is 1).
+
+        """
+        item.quality = max(MIN_QUALITY, item.quality - amount)
+
     def update_quality(self) -> None:
         """Update quality and sell_in for all items according to the business rules."""
         for item in self.items: