diff --git a/Assets/VRM/Runtime/LookAt/CurveMapper.cs b/Assets/VRM/Runtime/LookAt/CurveMapper.cs
index 6f9b0490c9..15069c1de4 100644
--- a/Assets/VRM/Runtime/LookAt/CurveMapper.cs
+++ b/Assets/VRM/Runtime/LookAt/CurveMapper.cs
@@ -62,7 +62,8 @@ IEnumerable<Keyframe> ToKeys(float[] values)
         public float Map(float src)
         {
             // https://github.com/vrm-c/UniVRM/issues/2452
-            return Curve.Evaluate(Mathf.Clamp(src, 0, 1) / MathF.Max(CurveXRangeDegree, 0.001f)) * CurveYRangeDegree;
+            var t = Mathf.Clamp01(Mathf.Clamp(src, 0, 1) / MathF.Max(CurveXRangeDegree, 0.001f));
+            return Curve.Evaluate(t) * CurveYRangeDegree;
         }
 
         public bool Equals(CurveMapper other)
diff --git a/Assets/VRM10/Runtime/Components/LookAt/CurveMapper.cs b/Assets/VRM10/Runtime/Components/LookAt/CurveMapper.cs
index 8beaf22c6f..a2be36e4e8 100644
--- a/Assets/VRM10/Runtime/Components/LookAt/CurveMapper.cs
+++ b/Assets/VRM10/Runtime/Components/LookAt/CurveMapper.cs
@@ -30,7 +30,8 @@ public void OnValidate()
         public float Map(float src)
         {
             // https://github.com/vrm-c/UniVRM/issues/2452
-            return Mathf.Clamp(src, 0, CurveXRangeDegree) / Mathf.Max(0.001f, CurveXRangeDegree) * CurveYRangeDegree;
+            var t = Mathf.Clamp01(Mathf.Clamp(src, 0, CurveXRangeDegree) / Mathf.Max(0.001f, CurveXRangeDegree));
+            return t * CurveYRangeDegree;
         }
     }
 }
\ No newline at end of file