diff --git a/DESCRIPTION b/DESCRIPTION
index 4b87b197..fff80fe2 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -64,7 +64,7 @@ Suggests:
     rstudioapi
 Config/Needs/check: Nowosad/spDataLarge, lwgeom
 Config/Needs/coverage: Nowosad/spDataLarge, lwgeom
-Config/Needs/website: bookdown, geofacet, rmarkdown, mapview, sits, r-spatial/leafem, mapsf, r-tmap/tmap.glyphs, r-tmap/tmap.networks, r-tmap/tmap.deckgl, sfnetworks
+Config/Needs/website: bookdown, geofacet, rmarkdown, mapview, sits, r-spatial/leafem, mapsf, r-tmap/tmap.glyphs, r-tmap/tmap.networks, r-tmap/tmap.deckgl, sfnetworks, r-tmap/tmap.cartogram
 Config/testthat/edition: 3
 Encoding: UTF-8
 LazyData: true
diff --git a/vignettes/foundations_crs.Rmd b/vignettes/foundations_crs.Rmd
index 401481dc..4edf083d 100644
--- a/vignettes/foundations_crs.Rmd
+++ b/vignettes/foundations_crs.Rmd
@@ -86,10 +86,11 @@ tm_title("Latitude/longitude (4326) coordinates")
 ```
 
 
-
 However, this is not a good map because areas near the poles are too large (and therefore overemphasized).
 
 ```{r, fig.height = 4}
+library(tmap.cartogram)
+
 # split multi-polygon countries (otherwise Alaska is still too large)
 World_polygons = sf::st_cast(World, "POLYGON")
 World_polygons$area = sf::st_area(World_polygons)