diff --git a/dat/yendor.des b/dat/yendor.des
index ea27c871b..df937fa1a 100644
--- a/dat/yendor.des
+++ b/dat/yendor.des
@@ -30,6 +30,8 @@ TELEPORT_REGION:levregion(01,00,79,20),(0,0,27,12)
 # Make it a morgue for rm id in mkmaze.c
 # for the purpose of random sdoor placement
 REGION:(12,01,20,09),unlit,"morgue",unfilled
+# another region to constrain monster arrival
+REGION:(01,01,10,11),unlit,"ordinary",unfilled
 MAZEWALK:(28,05),east
 LADDER:(06,05),down
 # Non diggable walls
@@ -111,6 +113,8 @@ STAIR:levregion(01,00,79,20),(0,0,28,12),up
 STAIR:levregion(01,00,79,20),(0,0,28,12),down
 BRANCH:levregion(01,00,79,20),(0,0,28,12)
 TELEPORT_REGION:levregion(01,00,79,20),(0,0,27,12)
+# entire tower in a region, constrains monster migration
+REGION:(01,01,26,11),unlit,"ordinary",unfilled
 REGION:(09,03,17,09),unlit,"zoo"
 DOOR:closed,(15,02)
 DOOR:closed,(11,10)
diff --git a/doc/fixes34.4 b/doc/fixes34.4
index 796ad2a9f..a1e9563e9 100644
--- a/doc/fixes34.4
+++ b/doc/fixes34.4
@@ -257,6 +257,7 @@ prevent obj_is_local panic during bones creation when splatter_burning_oil()
 	from a thrown potion of oil kills the hero
 fix region timeout detection, caused strange display of stinking cloud
 	while wearing the Eyes of the Overworld
+try to keep migrating monsters from escaping the wizard tower
 
 
 Platform- and/or Interface-Specific Fixes