diff --git a/data/core/terrain-graphics.cfg b/data/core/terrain-graphics.cfg
index 3ede7d03d9a9..13b94a0c42f1 100644
--- a/data/core/terrain-graphics.cfg
+++ b/data/core/terrain-graphics.cfg
@@ -888,7 +888,7 @@ C*,K*,X*,Q*,W*,Ai,M*,*^V*,*^B*,_off^_usr#enddef
 {NEW:TRANSITION            (Ms,Ha)          (W*,S*)                     -171               hills/snow-to-water}
 {NEW:TRANSITION            (Ms,Ha)          (!,Ha,Qx*,Mm,Ms,Md)         -172               hills/snow}
 
-{NEW:TRANSITION            (Tb,*^Uf*)       (!,M*,Tb)                   -184               forest/mushroom-base}
+{NEW:TRANSITION            (Tb,*^Uf*)       (!,M*,Tb,*^Uf*)             -184               forest/mushroom-base}
 {NEW:TRANSITION            (Mm,Hh)          (!,M*,Hh,Ai,W*,S*)          -180               hills/regular}
 {NEW:TRANSITION            (Md,Hhd)         (!,M*,Hhd,Ai,W*,S*)         -183               hills/dry}
 {NEW:TRANSITION            Hd               (!,Hd,Qx*,W*)               -184               hills/desert}