diff --git a/osu.Game/Beatmaps/ControlPoints/ControlPoint.cs b/osu.Game/Beatmaps/ControlPoints/ControlPoint.cs
index fd06c898ab..b91d609849 100644
--- a/osu.Game/Beatmaps/ControlPoints/ControlPoint.cs
+++ b/osu.Game/Beatmaps/ControlPoints/ControlPoint.cs
@@ -28,7 +28,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// </summary>
         /// <param name="existing">An existing control point to compare with.</param>
         /// <returns>Whether this <see cref="ControlPoint"/> is redundant when placed alongside <paramref name="existing"/>.</returns>
-        public abstract bool IsRedundant(ControlPoint existing);
+        public abstract bool IsRedundant(ControlPoint? existing);
 
         /// <summary>
         /// Create an unbound copy of this control point.
diff --git a/osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs b/osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs
index 6f624d20c9..c199d1da59 100644
--- a/osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs
+++ b/osu.Game/Beatmaps/ControlPoints/DifficultyControlPoint.cs
@@ -40,7 +40,7 @@ namespace osu.Game.Beatmaps.ControlPoints
             set => SliderVelocityBindable.Value = value;
         }
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => existing is DifficultyControlPoint existingDifficulty
                && SliderVelocity == existingDifficulty.SliderVelocity;
 
diff --git a/osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs b/osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs
index 365d024035..ead07b4eaa 100644
--- a/osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs
+++ b/osu.Game/Beatmaps/ControlPoints/EffectControlPoint.cs
@@ -67,7 +67,7 @@ namespace osu.Game.Beatmaps.ControlPoints
             set => KiaiModeBindable.Value = value;
         }
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => !OmitFirstBarLine
                && existing is EffectControlPoint existingEffect
                && KiaiMode == existingEffect.KiaiMode
diff --git a/osu.Game/Beatmaps/ControlPoints/SampleControlPoint.cs b/osu.Game/Beatmaps/ControlPoints/SampleControlPoint.cs
index ab575dfeda..78dec67937 100644
--- a/osu.Game/Beatmaps/ControlPoints/SampleControlPoint.cs
+++ b/osu.Game/Beatmaps/ControlPoints/SampleControlPoint.cs
@@ -72,7 +72,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         public virtual HitSampleInfo ApplyTo(HitSampleInfo hitSampleInfo)
             => hitSampleInfo.With(newBank: hitSampleInfo.Bank ?? SampleBank, newVolume: hitSampleInfo.Volume > 0 ? hitSampleInfo.Volume : SampleVolume);
 
-        public override bool IsRedundant(ControlPoint existing)
+        public override bool IsRedundant(ControlPoint? existing)
             => existing is SampleControlPoint existingSample
                && SampleBank == existingSample.SampleBank
                && SampleVolume == existingSample.SampleVolume;
diff --git a/osu.Game/Beatmaps/ControlPoints/TimingControlPoint.cs b/osu.Game/Beatmaps/ControlPoints/TimingControlPoint.cs
index 87ef4e86d5..23d4d10fd8 100644
--- a/osu.Game/Beatmaps/ControlPoints/TimingControlPoint.cs
+++ b/osu.Game/Beatmaps/ControlPoints/TimingControlPoint.cs
@@ -69,7 +69,7 @@ namespace osu.Game.Beatmaps.ControlPoints
         public double BPM => 60000 / BeatLength;
 
         // Timing points are never redundant as they can change the time signature.
-        public override bool IsRedundant(ControlPoint existing) => false;
+        public override bool IsRedundant(ControlPoint? existing) => false;
 
         public override void CopyFrom(ControlPoint other)
         {
diff --git a/osu.Game/Beatmaps/Formats/LegacyDecoder.cs b/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
index cc6a9126bd..a5e6ac0a1c 100644
--- a/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
@@ -213,7 +213,7 @@ namespace osu.Game.Beatmaps.Formats
                 return baseInfo;
             }
 
-            public override bool IsRedundant(ControlPoint existing)
+            public override bool IsRedundant(ControlPoint? existing)
                 => base.IsRedundant(existing)
                    && existing is LegacySampleControlPoint existingSample
                    && CustomSampleBank == existingSample.CustomSampleBank;