diff --git a/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/Colour/TaikoColourDifficultyPreprocessor.cs b/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/Colour/TaikoColourDifficultyPreprocessor.cs
index 0d1d3cd7a9..81ba219bc0 100644
--- a/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/Colour/TaikoColourDifficultyPreprocessor.cs
+++ b/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/Colour/TaikoColourDifficultyPreprocessor.cs
@@ -77,7 +77,7 @@ private static List<MonoEncoding> encodeMono(List<DifficultyHitObject> data)
                 TaikoDifficultyHitObject? previousObject = taikoObject.PreviousNote(0);
 
                 // If this is the first object in the list or the colour changed, create a new mono encoding
-                if (currentEncoding == null || (taikoObject.BaseObject as Hit)?.Type != (previousObject?.BaseObject as Hit)?.Type)
+                if (currentEncoding == null || previousObject == null || (taikoObject.BaseObject as Hit)?.Type != (previousObject.BaseObject as Hit)?.Type)
                 {
                     currentEncoding = new MonoEncoding();
                     encodings.Add(currentEncoding);