diff --git a/Assets/Coffee/UIExtensions/SoftMaskForUGUI/Scripts/SoftMask.cs b/Assets/Coffee/UIExtensions/SoftMaskForUGUI/Scripts/SoftMask.cs
index 644fec7..50e970f 100644
--- a/Assets/Coffee/UIExtensions/SoftMaskForUGUI/Scripts/SoftMask.cs
+++ b/Assets/Coffee/UIExtensions/SoftMaskForUGUI/Scripts/SoftMask.cs
@@ -239,8 +239,8 @@ namespace Coffee.UIExtensions
 				return true;
 			}
 
-			int x = (int)(softMaskBuffer.width * sp.x / Screen.width);
-			int y = (int)(softMaskBuffer.height * sp.y / Screen.height);
+			int x = (int)((softMaskBuffer.width - 1) * Mathf.Clamp01(sp.x / Screen.width));
+			int y = (int)((softMaskBuffer.height - 1) * Mathf.Clamp01(sp.y / Screen.height));
 			return 0.5f < GetPixelValue(x, y, interactions);
 		}