diff --git a/overviewer_core/tileset.py b/overviewer_core/tileset.py
index 9d886de..01a6f54 100644
--- a/overviewer_core/tileset.py
+++ b/overviewer_core/tileset.py
@@ -595,8 +595,8 @@ class TileSet(object):
                     # Computes the path in the quadtree from the col,row coordinates
                     tile = RenderTile.compute_path(c, r, depth)
 
-                    if forcerender:
-                        # forcerender mode: Skip all other checks, mark tiles
+                    if markall:
+                        # markall mode: Skip all other checks, mark tiles
                         # as dirty unconditionally
                         dirty.add(tile.path)
                         continue