diff --git a/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/pose_samplers.py b/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/pose_samplers.py
index a4b6d02..2bce7b2 100644
--- a/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/pose_samplers.py
+++ b/exts/omni.ext.mobility_gen/omni/ext/mobility_gen/pose_samplers.py
@@ -112,8 +112,7 @@ def sample_px(self, occupancy_map: OccupancyMap) -> Pose2d:
         mask = occupancy_map.freespace_mask()
 
         block_mask = np.zeros_like(mask)
-        block_mask[block_x_min:block_x_min+block_size_px] = True
-        block_mask[block_y_min:block_y_min+block_size_px] = True
+        block_mask[block_y_min:block_y_min+block_size_px, block_x_min:block_x_min+block_size_px] = True
 
         net_mask = block_mask & mask