diff --git a/logic/service/player/Monster.go b/logic/service/player/Monster.go
index 10c022ec..1494dc46 100644
--- a/logic/service/player/Monster.go
+++ b/logic/service/player/Monster.go
@@ -200,7 +200,7 @@ func replaceOneNumber(original [3]int) ([3]int, int, int) {
 		originalMap[num] = true
 	}
 
-	for i := 0; i < 8; i++ {
+	for i := 0; i < 9; i++ {
 		if !originalMap[i] {
 			candidates = append(candidates, i)
 		}