diff --git a/R/plot_slope.R b/R/plot_slope.R
index f431f86..c6b76b8 100644
--- a/R/plot_slope.R
+++ b/R/plot_slope.R
@@ -51,7 +51,22 @@ plot_slope = function(
     )
   }
   dz = distance_z(route_xyz, lonlat = lonlat)
-  plot_dz(dz$d, dz$z, seq_brks = seq_brks, brks = brks, ...)
+  plot_dz(
+    d = dz$d,
+    z = dz$z,
+    fill = fill,
+    horiz = horiz,
+    pal = pal,
+    legend_position = legend_position,
+    col = col,
+    cex = cex,
+    bg = bg,
+    title = title,
+    brks = brks,
+    seq_brks = seq_brks,
+    ncol = ncol,
+    ...
+    )
 }
 #' Plot a digital elevation profile based on xyz data
 #'
diff --git a/R/slope_get.R b/R/slope_get.R
index 2becad7..e4c7cae 100644
--- a/R/slope_get.R
+++ b/R/slope_get.R
@@ -7,6 +7,8 @@
 #' @examples
 #' # Time-consuming examples that require an internet connectioin and API key:
 #' \donttest{
+#' library(sf)
+#' library(raster)
 #' routes = cyclestreets_route
 #' e = elevation_get(routes)
 #' class(e)
diff --git a/R/slopes.R b/R/slopes.R
index 715e55a..244b450 100644
--- a/R/slopes.R
+++ b/R/slopes.R
@@ -215,7 +215,7 @@ slope_xyz = function(route_xyz, fun = slope_matrix_weighted, lonlat = TRUE) {
 #' elevation_extract(m, dem, method = "simple")
 #' # Test with terra (requires internet connection):
 #' \donttest{
-#' if(has_terra()) {
+#' if(slopes:::has_terra()) {
 #' u = paste0("https://github.com/ITSLeeds/slopes/",
 #'    "releases/download/0.0.0/dem_lisbon.tif" )
 #' if(!file.exists("dem_lisbon.tif")) download.file(u, "dem_lisbon.tif")
diff --git a/man/elevation_extract.Rd b/man/elevation_extract.Rd
index 8cfd857..cae7fe1 100644
--- a/man/elevation_extract.Rd
+++ b/man/elevation_extract.Rd
@@ -34,7 +34,7 @@ elevation_extract(m, dem)
 elevation_extract(m, dem, method = "simple")
 # Test with terra (requires internet connection):
 \donttest{
-if(has_terra()) {
+if(slopes:::has_terra()) {
 u = paste0("https://github.com/ITSLeeds/slopes/",
    "releases/download/0.0.0/dem_lisbon.tif" )
 if(!file.exists("dem_lisbon.tif")) download.file(u, "dem_lisbon.tif")
diff --git a/man/elevation_get.Rd b/man/elevation_get.Rd
index 0f1b087..424e212 100644
--- a/man/elevation_get.Rd
+++ b/man/elevation_get.Rd
@@ -20,6 +20,8 @@ Get elevation data from hosted maptile services
 \examples{
 # Time-consuming examples that require an internet connectioin and API key:
 \donttest{
+library(sf)
+library(raster)
 routes = cyclestreets_route
 e = elevation_get(routes)
 class(e)