diff --git a/osu.Game.Rulesets.Catch/Objects/JuiceStream.cs b/osu.Game.Rulesets.Catch/Objects/JuiceStream.cs
index 4d68bf592c..b014b32305 100644
--- a/osu.Game.Rulesets.Catch/Objects/JuiceStream.cs
+++ b/osu.Game.Rulesets.Catch/Objects/JuiceStream.cs
@@ -113,7 +113,7 @@ namespace osu.Game.Rulesets.Catch.Objects
         public double EndTime
         {
             get => StartTime + this.SpanCount() * Path.Distance / Velocity;
-            set => throw new System.NotImplementedException();
+            set => throw new System.NotSupportedException($"Adjust via {nameof(RepeatCount)} instead"); // can be implemented if/when needed.
         }
 
         public float EndX => X + this.CurvePositionAt(1).X / CatchPlayfield.BASE_WIDTH;
diff --git a/osu.Game.Rulesets.Osu/Objects/Slider.cs b/osu.Game.Rulesets.Osu/Objects/Slider.cs
index bab7e6dbee..95fb6d9d48 100644
--- a/osu.Game.Rulesets.Osu/Objects/Slider.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Slider.cs
@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Osu.Objects
         public double EndTime
         {
             get => StartTime + this.SpanCount() * Path.Distance / Velocity;
-            set => throw new System.NotImplementedException();
+            set => throw new System.NotSupportedException($"Adjust via {nameof(RepeatCount)} instead"); // can be implemented if/when needed.
         }
 
         public double Duration => EndTime - StartTime;
diff --git a/osu.Game/Rulesets/Objects/Legacy/ConvertSlider.cs b/osu.Game/Rulesets/Objects/Legacy/ConvertSlider.cs
index b5cd9be245..53cdf457c4 100644
--- a/osu.Game/Rulesets/Objects/Legacy/ConvertSlider.cs
+++ b/osu.Game/Rulesets/Objects/Legacy/ConvertSlider.cs
@@ -29,7 +29,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
         public double EndTime
         {
             get => StartTime + this.SpanCount() * Distance / Velocity;
-            set => throw new System.NotImplementedException();
+            set => throw new System.NotSupportedException($"Adjust via {nameof(RepeatCount)} instead"); // can be implemented if/when needed.
         }
 
         public double Duration => EndTime - StartTime;