diff --git a/rogueviz/ru/globals.cpp b/rogueviz/ru/globals.cpp
index 8d3f4d7a..8cb34f2c 100644
--- a/rogueviz/ru/globals.cpp
+++ b/rogueviz/ru/globals.cpp
@@ -59,7 +59,7 @@ enum eWall {
   wAir, wWall, wBouncy, wSpike, wWater, wFrozen, wDoor, wSmashedDoor,
   wLockedDoor, wFountain, wBluePortal, wOrangePortal, wPlatform, wStaircase,
   wColumn, wForge, wWoodWall, wShopDoor, wSecretPassage, wSign, wWallSign, wTimeDoor, 
-  wBottomSpike, wGUARD };
+  wBottomSpike, wRogueWallHidden, wRogueWall, wGUARD };
 
 flagtype W_BLOCK = 1;
 flagtype W_TRANS = 2;
@@ -98,6 +98,8 @@ ruwall walls[qwall] = {
   {"wall sign", "X", 0xFFFFC0FF, W_BLOCK, "You need to wait close to this sign to read it."},
   {"time door", "#", 0x8080FFFF, W_BLOCK | W_STABLE, "A powerful door, opened by a mechanism."},
   {"bottom spike", "v", 0xC08080FF, W_TRANS | W_PAIN | W_BLOCKBIRD | W_DOWNWARD, "A downward-pointing spike. You can fall from above through it safely, but otherwise, it is very dangerous."},
+  {"wall", "#", 0xFFFFFFFF, W_BLOCK | W_STABLE, "These kinds of tough walls can never be destroyed."},
+  {"fake wall", "#", 0x404080FF, W_PLATFORM | W_STABLE | W_BLOCKBIRD, "Your rogueish senses have discovered that this wall is fake."},
   };
 
 int sel = 1;
diff --git a/rogueviz/ru/render.cpp b/rogueviz/ru/render.cpp
index 6b7ea457..b1a84eba 100644
--- a/rogueviz/ru/render.cpp
+++ b/rogueviz/ru/render.cpp
@@ -283,9 +283,16 @@ void man::draw() {
       int cx = int(h.x / block_x);
       int cy = int(h.y / block_y);
       if(cx < 0 || cy < 0 || cx >= room_x || cy >= room_y) break;
-      if(!(walls[current_room->at(cx, cy)].flags & W_TRANS)) break;
+      auto what = current_room->at(cx, cy);
+      if(what == wRogueWallHidden) {
+        current_room->replace_block_frev(cx, cy, wRogueWall);
+        addMessage("You discover a secret door!");
+        }
+      if(!(walls[what].flags & W_TRANS)) break;
       }
+    vid.linewidth *= 3;
     queuecurve(scrm, 0x800080, 0, PPR::LINE);
+    vid.linewidth /= 3;
     }
   }
 
diff --git a/rogueviz/ru/save.cpp b/rogueviz/ru/save.cpp
index 62b36703..6aa1570b 100644
--- a/rogueviz/ru/save.cpp
+++ b/rogueviz/ru/save.cpp
@@ -39,6 +39,7 @@ void save_map(string fname) {
     for(int y=0; y<room_y; y++)
     for(int x=0; x<room_x; x++) {
       auto i = r.block_at[y][x] >> 3;
+      if(i == int(wRogueWallHidden)) i = int(wRogueWall);
       auto& c = code_for[i];
       if(c == 0 && !code_used.count(walls[i].glyph[0])) c = walls[i].glyph[0];
       if(c == 0) c = next_code++;
@@ -52,6 +53,7 @@ void save_map(string fname) {
     for(int y=0; y<room_y; y++) {
       for(int x=0; x<room_x; x++) {
         auto v = r.block_at[y][x];
+        if(v == int(wRogueWallHidden)) v = int(wRogueWall);
         print(f, format("%c", (v & 7) == 7 ? 'b' : code_for[v>>3]));
         }
       println(f);
@@ -106,6 +108,8 @@ void load_room(fhstream& f, cell *c) {
     string t = s.substr(2);
     if(s.size() < 3 || s[1] != ' ') err("load codes", s);
     for(int i=0; i<qwall; i++) if(walls[i].name == t) {
+      if(i == int(wRogueWall)) i = int(wRogueWallHidden);
+      if(i == int(wSmashedDoor)) i = int(wDoor);
       codes[s[0]] = i;
       break;
       }