diff --git a/src/AcDream.App/Rendering/GameWindow.cs b/src/AcDream.App/Rendering/GameWindow.cs
index 71a6f558..a2531674 100644
--- a/src/AcDream.App/Rendering/GameWindow.cs
+++ b/src/AcDream.App/Rendering/GameWindow.cs
@@ -7073,10 +7073,24 @@ public sealed class GameWindow : IDisposable
                 // so it doesn't get frustum-culled when the player walks away from
                 // the spawn landblock. Without this, the entity stays in the spawn
                 // landblock's entity list and disappears when that landblock is culled.
-                var pp = _playerController.Position;
-                int plx = _liveCenterX + (int)System.Math.Floor(pp.X / 192f);
-                int ply = _liveCenterY + (int)System.Math.Floor(pp.Y / 192f);
-                uint currentLb = (uint)((plx << 24) | (ply << 16) | 0xFFFF);
+                uint currentLb;
+                if (result.CellId != 0 && (result.CellId & 0xFFFFu) >= 0x0100u)
+                {
+                    // Indoor cell (dungeon/building EnvCell): the entity's landblock is
+                    // the CELL's landblock. Dungeon EnvCells sit at arbitrary "ocean"
+                    // world coords with negative local-Y, so floor(pp.Y/192) lands one
+                    // landblock off (the Bug-A class) — relocating the player into the
+                    // landblock the dungeon collapse unloaded, making the avatar
+                    // invisible. The cell id is authoritative.
+                    currentLb = (result.CellId & 0xFFFF0000u) | 0xFFFFu;
+                }
+                else
+                {
+                    var pp = _playerController.Position;
+                    int plx = _liveCenterX + (int)System.Math.Floor(pp.X / 192f);
+                    int ply = _liveCenterY + (int)System.Math.Floor(pp.Y / 192f);
+                    currentLb = (uint)((plx << 24) | (ply << 16) | 0xFFFF);
+                }
                 _worldState.RelocateEntity(pe, currentLb);
             }