diff --git a/mlab/citydeclouds/castle/cwdccastleb8 b/mlab/citydeclouds/castle/cwdccastleb8
index 46c7ac0b7..b3740a72f 100644
--- a/mlab/citydeclouds/castle/cwdccastleb8
+++ b/mlab/citydeclouds/castle/cwdccastleb8
@@ -99395,6 +99395,13 @@ arch dirtfloor
 x 59
 y 56
 end
+arch stair3_ystone_do
+slaying cwdccastleb9
+hp 6
+sp 5
+x 59
+y 56
+end
 arch dirtfloor
 x 59
 y 57