diff --git a/osu.Game/Screens/Play/HUD/InputTrigger.cs b/osu.Game/Screens/Play/HUD/InputTrigger.cs
index 93b45daab3..b57f2cdf91 100644
--- a/osu.Game/Screens/Play/HUD/InputTrigger.cs
+++ b/osu.Game/Screens/Play/HUD/InputTrigger.cs
@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System;
 using osu.Framework.Graphics;
 
 namespace osu.Game.Screens.Play.HUD
@@ -11,8 +10,20 @@ namespace osu.Game.Screens.Play.HUD
     /// </summary>
     public abstract partial class InputTrigger : Component
     {
-        public event Action<bool>? OnActivate;
-        public event Action<bool>? OnDeactivate;
+        /// <summary>
+        /// Callback to invoke when the associated input has been activated.
+        /// </summary>
+        /// <param name="forwardPlayback">Whether gameplay is progressing in the forward direction time-wise.</param>
+        public delegate void OnActivateCallback(bool forwardPlayback);
+
+        /// <summary>
+        /// Callback to invoke when the associated input has been deactivated.
+        /// </summary>
+        /// <param name="forwardPlayback">Whether gameplay is progressing in the forward direction time-wise.</param>
+        public delegate void OnDeactivateCallback(bool forwardPlayback);
+
+        public event OnActivateCallback? OnActivate;
+        public event OnDeactivateCallback? OnDeactivate;
 
         protected InputTrigger(string name)
         {