diff --git a/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRoll.cs b/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRoll.cs
index dcbdfa270d..3551538fe7 100644
--- a/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRoll.cs
+++ b/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRoll.cs
@@ -9,7 +9,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
 {
     public class DrawableDrumRoll : DrawableTaikoHitObject
     {
-        private DrumRoll drumRoll;
+        private readonly DrumRoll drumRoll;
 
         public DrawableDrumRoll(DrumRoll drumRoll)
             : base(drumRoll)
diff --git a/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRollTick.cs b/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRollTick.cs
index 83d878d293..360cccd6ca 100644
--- a/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRollTick.cs
+++ b/osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRollTick.cs
@@ -16,9 +16,9 @@ public class DrawableDrumRollTick : DrawableTaikoHitObject
         /// A list of keys which this HitObject will accept. These are the standard Taiko keys for now.
         /// These should be moved to bindings later.
         /// </summary>
-        private List<Key> validKeys = new List<Key>(new[] { Key.D, Key.F, Key.J, Key.K });
+        private readonly List<Key> validKeys = new List<Key>(new[] { Key.D, Key.F, Key.J, Key.K });
 
-        private DrumRollTick tick;
+        private readonly DrumRollTick tick;
 
         public DrawableDrumRollTick(DrumRollTick tick)
             : base(tick)