diff --git a/docs/G306.txt b/docs/G306.txt
index ef3dc7c..5913017 100644
--- a/docs/G306.txt
+++ b/docs/G306.txt
@@ -743,7 +743,8 @@
 		"type": "bool",
 		"cur": false,
 		"default": false,
-		"size": 4
+		"size": 4,
+		"depend_or": ["mode==24位彩色"]
 	},
 	"is-anti-skew": {
 		"cat": "base",