diff --git a/osu.Game/Rulesets/Difficulty/PerformanceCalculator.cs b/osu.Game/Rulesets/Difficulty/PerformanceCalculator.cs
index abfe8a6db1..6358ec18b7 100644
--- a/osu.Game/Rulesets/Difficulty/PerformanceCalculator.cs
+++ b/osu.Game/Rulesets/Difficulty/PerformanceCalculator.cs
@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Audio.Track;
 using osu.Framework.Extensions.IEnumerableExtensions;