diff --git a/osu.Game/Graphics/Containers/OsuScrollContainer.cs b/osu.Game/Graphics/Containers/OsuScrollContainer.cs
index df4c3a3324..ab72276ad0 100644
--- a/osu.Game/Graphics/Containers/OsuScrollContainer.cs
+++ b/osu.Game/Graphics/Containers/OsuScrollContainer.cs
@@ -85,6 +85,8 @@ namespace osu.Game.Graphics.Containers
 
         protected override bool OnScroll(ScrollEvent e)
         {
+            // allow for controlling volume when alt is held.
+            // mostly for compatibility with osu-stable.
             if (e.AltPressed) return false;
 
             return base.OnScroll(e);