diff --git a/doc/fixes36.1 b/doc/fixes36.1
index 863bd0798..8f01b89a3 100644
--- a/doc/fixes36.1
+++ b/doc/fixes36.1
@@ -463,6 +463,7 @@ when poly'd into a giant and moving onto a boulder's spot, you could get "you
 improve #adjust command's handling of the '$' and '#' inventory slots
 prevent #adjust from allowing anything to be moved into the special '-' slot
 sometimes rings dropped into sinks can be found in the pipes
+doors in special levels were always generated in vertical orientation
 
 
 Fixes to Post-3.6.0 Problems that Were Exposed Via git Repository
diff --git a/include/rm.h b/include/rm.h
index 18b33050b..9a0ce5343 100644
--- a/include/rm.h
+++ b/include/rm.h
@@ -85,7 +85,8 @@ enum levl_typ_types {
 #define IS_STWALL(typ) ((typ) <= DBWALL) /* STONE <= (typ) <= DBWALL */
 #define IS_ROCK(typ) ((typ) < POOL)      /* absolutely nonaccessible */
 #define IS_DOOR(typ) ((typ) == DOOR)
-#define IS_TREE(typ) \
+#define IS_DOORJOIN(typ) (IS_ROCK(typ) || (typ) == IRONBARS)
+#define IS_TREE(typ)                                            \
     ((typ) == TREE || (level.flags.arboreal && (typ) == STONE))
 #define ACCESSIBLE(typ) ((typ) >= DOOR) /* good position */
 #define IS_ROOM(typ) ((typ) >= ROOM)    /* ROOM, STAIRS, furniture.. */
diff --git a/src/sp_lev.c b/src/sp_lev.c
index badbab319..fc1dcf9e1 100644
--- a/src/sp_lev.c
+++ b/src/sp_lev.c
@@ -4191,6 +4191,13 @@ genericptr_t arg;
         if (typ < D_CLOSED)
             typ = D_CLOSED;
     }
+
+    if (((isok(x-1,y) && IS_DOORJOIN(levl[x-1][y].typ)) || !isok(x-1,y))
+        || (isok(x+1,y) && IS_DOORJOIN(levl[x+1][y].typ)) || !isok(x+1,y))
+        levl[x][y].horizontal = 1;
+    else
+        levl[x][y].horizontal = 0;
+
     levl[x][y].doormask = typ;
     SpLev_Map[x][y] = 1;
 }