diff --git a/ch3-asm/ch3-06-func-again.md b/ch3-asm/ch3-06-func-again.md
index 68a65ab..26b9386 100644
--- a/ch3-asm/ch3-06-func-again.md
+++ b/ch3-asm/ch3-06-func-again.md
@@ -192,7 +192,7 @@ func MyInt_Twice(v MyInt) int {
 // func (v MyInt) Twice() int
 TEXT ·MyInt·Twice(SB), NOSPLIT, $0-16
 	MOVQ a+0(FP), AX   // v
-	MOVQ AX, AX        // AX *= 2
+	ADDQ AX, AX        // AX *= 2
 	MOVQ AX, ret+8(FP) // return v
 	RET
 ```