diff --git a/ch2-cgo/ch2-05-class.md b/ch2-cgo/ch2-05-class.md
index 6b94b0f..d2df707 100644
--- a/ch2-cgo/ch2-05-class.md
+++ b/ch2-cgo/ch2-05-class.md
@@ -199,6 +199,8 @@ import "unsafe"
 
 func main() {
 	buf := NewMyBuffer(1024)
+	defer buf.Delete()
+
 	copy(buf.Data(), []byte("hello\x00"))
 	C.puts((*C.char)(unsafe.Pointer(&(buf.Data()[0]))))
 }
diff --git a/examples/ch2-05/class-cc2go/main.go b/examples/ch2-05/class-cc2go/main.go
index 7d6d51e..d487d53 100644
--- a/examples/ch2-05/class-cc2go/main.go
+++ b/examples/ch2-05/class-cc2go/main.go
@@ -6,6 +6,8 @@ import "unsafe"
 
 func main() {
 	buf := NewMyBuffer(1024)
+	defer buf.Delete()
+
 	copy(buf.Data(), []byte("hello\x00"))
 	C.puts((*C.char)(unsafe.Pointer(&(buf.Data()[0]))))
 }