diff --git a/R/tree.detection.Rmd b/R/tree.detection.Rmd
index 30608d018e924c0bec72698ca3f21cd60491f40e..09c1c3068354583e48f1591863e2eecb08fd1357 100644
--- a/R/tree.detection.Rmd
+++ b/R/tree.detection.Rmd
@@ -302,7 +302,7 @@ Before computation of point cloud metrics in each segment, the whole point cloud
 # normalize point cloud
 lasn <- lidR::normalize_height(laschablais3, lidR::tin())
 # add segment id in LAS object
-lasn@data$seg.id <- raster::extract(segms[["segments.id"]], lasn@data[,1:2])
+lasn <- lidR::add_attribute(lasn, raster::extract(segms[["segments.id"]], lasn@data[,1:2]), "seg.id")
 # split las object by segment id
 lasl <- split(lasn@data,lasn@data$seg.id)
 # convert list of data.frames to list of las objects