diff --git a/vendor/clouds3d.js b/vendor/clouds3d.js
index 6c6eaed..356b5cd 100644
--- a/vendor/clouds3d.js
+++ b/vendor/clouds3d.js
@@ -351,12 +351,13 @@ function drawTileAt(lng, perp, dx, dz, centerTileX, centerTileY) {
         // the corridor orientation (east tiles have their image east
         // on the left of the drawn area, west tiles on the right).
         // Labels are drawn separately in normal orientation, so the
-        // Draw image with normal orientation (no X-flip). The
-        // X-swap arrangement (canvasX = -perp + ...) already places
-        // east tiles on the right of the screen, so the X coordinates
-        // read naturally left to right when scanning the corridor.
-        groundCtx.drawImage(img, canvasX, canvasY,
-            GROUND_TILE_SIZE, GROUND_TILE_SIZE);
+        // X-flip the image (NS-mirror). The arrangement uses the
+        // natural order (canvasX = perp + ...) so east tiles are on
+        // the LEFT of the screen. The image X-flip makes image east
+        // appear on the right of each east tile (the natural map
+        // orientation).
+        groundCtx.drawImage(img, canvasX + GROUND_TILE_SIZE, canvasY,
+            -GROUND_TILE_SIZE, GROUND_TILE_SIZE);
         groundLoadedTiles[tileX + '_' + tileY] = true;
 
         // Thin border so the user can see where one tile ends and the