diff --git a/dumas_h3_latent_upscale.py b/dumas_h3_latent_upscale.py
index 89f1b04..2b92cf8 100644
--- a/dumas_h3_latent_upscale.py
+++ b/dumas_h3_latent_upscale.py
@@ -634,9 +634,18 @@ def _upscale_video_model_tiled(video, param):
     spatial_h_overlap = max(0, int(param.get("spatial_h_overlap", overlap) or overlap))
     min_tile_size = max(0, int(param.get("min_tile_size", 0) or 0))
 
+    def _fit_overlap(value, tile):
+        value = max(0, int(value or 0))
+        tile = max(0, int(tile or 0))
+        if tile <= 32:
+            return 0
+        return min(value, ((tile - 1) // 32) * 32)
+
     if mode == "rows_cols":
         tile_w = max(32, int(round(w_out / float(grid_cols) / 32.0)) * 32)
         tile_h = max(32, int(round(h_out / float(grid_rows) / 32.0)) * 32)
+        spatial_w_overlap = _fit_overlap(spatial_w_overlap, tile_w)
+        spatial_h_overlap = _fit_overlap(spatial_h_overlap, tile_h)
         min_tile_size = min(min_tile_size, tile_w, tile_h)
         rows, cols, trows, tcols, row_ovl, col_ovl = _compute_spatial_grid(
             h_out, w_out, tile_h, tile_w, spatial_h_overlap, spatial_w_overlap, min_tile_size, min_tile_size
@@ -648,6 +657,7 @@ def _upscale_video_model_tiled(video, param):
             if value % 32 != 0:
                 raise ValueError(f"'{name}' must be a multiple of 32 pixels; got {value}.")
         min_tile_size = min(min_tile_size, tile_w, tile_h)
+        overlap = _fit_overlap(overlap, min(tile_w, tile_h))
         rows, cols, trows, tcols, row_ovl, col_ovl = _compute_spatial_grid(
             h_out, w_out, tile_h, tile_w, overlap, overlap, min_tile_size, min_tile_size
         )