diff --git a/osu.Game.Rulesets.Osu/Replays/OsuAutoGenerator.cs b/osu.Game.Rulesets.Osu/Replays/OsuAutoGenerator.cs
index 9d63949dcc..1cf6bc91f0 100644
--- a/osu.Game.Rulesets.Osu/Replays/OsuAutoGenerator.cs
+++ b/osu.Game.Rulesets.Osu/Replays/OsuAutoGenerator.cs
@@ -339,7 +339,8 @@ namespace osu.Game.Rulesets.Osu.Replays
 
             AddFrameToReplay(startFrame);
 
-            // ~477 as per stable.
+            // 0.05 rad/ms, or ~477 RPM, as per stable.
+            // the redundant conversion from RPM to rad/ms is here for ease of testing custom SPM specs.
             const float spin_rpm = 0.05f / (2 * MathF.PI) * 60000;
             float radsPerMillisecond = MathUtils.DegreesToRadians(spin_rpm * 360) / 60000;