diff --git a/example/ck_tile/01_fmha/mask.hpp b/example/ck_tile/01_fmha/mask.hpp
index 03e1537c5d..bc0cf1e25b 100644
--- a/example/ck_tile/01_fmha/mask.hpp
+++ b/example/ck_tile/01_fmha/mask.hpp
@@ -122,7 +122,7 @@ struct mask_info
                         v1   = atoi(v.substr(found_1 + 1).c_str());
                         sink = 0;
                     }
-                    tmp.type = mask_enum::mask_bottom_right;
+                    tmp.type = (v0 >= 0) ? mask_enum::window_generic : mask_enum::mask_bottom_right;
                     auto r   = ck_tile::make_generic_attention_mask_coordinates_from_lr_window(
                         v0, v1, sink, y_total, x_total, false);
                     tmp.y     = r.at(ck_tile::number<0>{});