diff --git a/robotgo.go b/robotgo.go
index dcbe045..86fee72 100644
--- a/robotgo.go
+++ b/robotgo.go
@@ -255,6 +255,7 @@ func GetXDisplayName() string {
 }
 
 // CaptureScreen capture the screen return bitmap(c struct)
+// use `defer robotgo.FreeBitmap(bitmap)` to free the bitmap
 func CaptureScreen(args ...int) C.MMBitmapRef {
 	var x, y, w, h C.size_t
 
@@ -797,6 +798,9 @@ func internalFindBitmap(bit, sbit C.MMBitmapRef, tolerance float64) (int, int) {
 //
 //  |tolerance| should be in the range 0.0f - 1.0f, denoting how closely the
 //  colors in the bitmaps need to match, with 0 being exact and 1 being any.
+// 
+// This method only automatically free the internal bitmap,
+// use `defer robotgo.FreeBitmap(bit)` to free the bitmap
 func FindBitmap(bit C.MMBitmapRef, args ...interface{}) (int, int) {
 	var (
 		sbit      C.MMBitmapRef
@@ -826,6 +830,8 @@ func FindBitmap(bit C.MMBitmapRef, args ...interface{}) (int, int) {
 //
 //	robotgo.FindPic(path string, subbitamp C.MMBitmapRef, tolerance float64)
 //
+// This method only automatically free the internal bitmap,
+// use `defer robotgo.FreeBitmap(bit)` to free the bitmap
 func FindPic(path string, args ...interface{}) (int, int) {
 	var (
 		sbit      C.MMBitmapRef