diff --git a/R/theme_ps.R b/R/theme_ps.R
index 1eddafa7..fef8268c 100644
--- a/R/theme_ps.R
+++ b/R/theme_ps.R
@@ -8,39 +8,40 @@
 #' @param plot.axes should the axes be shown?
 #' @param plot.legend should the legend(s) be shown?
 #' @export
-theme_ps <- function(base_size = 12, base_family = "", plot.axes=FALSE, plot.legend=FALSE) {
-	if (!requireNamespace("ggplot2", quietly = TRUE)) {
-		stop("ggplot2 package needed for this function to work. Please install it.",
-			 call. = FALSE)
-	} else {
-		replace <- function(e1, e2) {
-			e1[names(e2)] <- e2
-			e1	
-		}
-		
-		tps <- replace(ggplot2::theme_minimal(base_size = base_size, base_family = base_family),
-					   ggplot2::theme(panel.background = ggplot2::element_blank(), 
-					   			   panel.border = ggplot2::element_blank(), 
-					   			   panel.grid = ggplot2::element_blank(),
-					   			   strip.background = ggplot2::element_blank(), 
-					   			   plot.background = ggplot2::element_blank(), 
-					   			   plot.title = ggplot2::element_blank(),
-					   			   strip.text = ggplot2::element_blank(),
-					   			   panel.spacing = unit(0,"null"),
-					   			   plot.margin = rep(unit(0,"null"),4)))
-		
-		if (!plot.legend) {
-			tps <- replace(tps, ggplot2::theme(legend.position = "none"))
-		}
-		
-		if (plot.axes) {
-			tps
-		} else {
-			replace(tps, 
-					ggplot2::theme(axis.text = ggplot2::element_blank(),
-								   axis.title = ggplot2::element_blank(),
-								   axis.ticks = ggplot2::element_line(), 
-								   axis.ticks.length = unit(0, "lines")))
-		}
-	}
+theme_ps <- function(base_size = 12, base_family = "", plot.axes = FALSE, plot.legend = FALSE) {
+  rlang::check_installed("ggplot2", reason = "to create plot themes.")
+  replace <- function(e1, e2) {
+    e1[names(e2)] <- e2
+    e1
+  }
+  tps <- replace(
+    ggplot2::theme_minimal(base_size = base_size, base_family = base_family),
+    ggplot2::theme(
+      panel.background = ggplot2::element_blank(),
+      panel.border = ggplot2::element_blank(),
+      panel.grid = ggplot2::element_blank(),
+      strip.background = ggplot2::element_blank(),
+      plot.background = ggplot2::element_blank(),
+      plot.title = ggplot2::element_blank(),
+      strip.text = ggplot2::element_blank(),
+      panel.spacing = unit(0, "null"),
+      plot.margin = rep(unit(0, "null"), 4)
+    )
+  )
+  if (!plot.legend) {
+    tps <- replace(tps, ggplot2::theme(legend.position = "none"))
+  }
+  if (plot.axes) {
+    tps
+  } else {
+    replace(
+      tps,
+      ggplot2::theme(
+        axis.text = ggplot2::element_blank(),
+        axis.title = ggplot2::element_blank(),
+        axis.ticks = ggplot2::element_line(),
+        axis.ticks.length = unit(0, "lines")
+      )
+    )
+  }
 }
diff --git a/R/tmapGridAux.R b/R/tmapGridAux.R
index c5a40a05..735ec24b 100644
--- a/R/tmapGridAux.R
+++ b/R/tmapGridAux.R
@@ -11,8 +11,7 @@ findZoom = function(b) {
 
 tmapGridTilesPrep = function(a, bs, id, o) {
 	g = get("g", envir = .TMAP_GRID)
-	
-	if (!requireNamespace("maptiles")) stop("maptiles package is required", call. = FALSE)
+	rlang::check_installed("maptiles")
 	
 	
 	crs = sf::st_crs(bs[[1]])
diff --git a/R/tmapGridInit.R b/R/tmapGridInit.R
index bef31911..2b662133 100644
--- a/R/tmapGridInit.R
+++ b/R/tmapGridInit.R
@@ -1,6 +1,5 @@
 tmapGridInit = function(o, return.asp = FALSE, vp) {
-	if (!requireNamespace("grid")) stop("grid package required but not installed yet.")
-	
+	rlang::check_installed("grid")
 	
 	rows = with(o, {
 		x = c(outer.margins.top = outer.margins[3],
diff --git a/R/tmapLeafletInit.R b/R/tmapLeafletInit.R
index 9d9e6d60..d8466c51 100644
--- a/R/tmapLeafletInit.R
+++ b/R/tmapLeafletInit.R
@@ -33,7 +33,6 @@ addOverlayGroup <- function(group, are.tiles = FALSE) {
 
 tmapLeafletInit = function(o, return.asp = FALSE, vp) {
 	if (return.asp) return(1)
-	if (!requireNamespace("leaflet")) stop("leaflet package required but not installed yet.")
 
 	per_page = rep(o$ncols * o$nrows, o$npages)
 	k = o$ncols * o$nrows * o$npages
diff --git a/R/tmapShape.R b/R/tmapShape.R
index bdc1edd7..bfe52f88 100644
--- a/R/tmapShape.R
+++ b/R/tmapShape.R
@@ -94,7 +94,7 @@ tmapShape.Raster = function(shp, is.main, crs, bbox, unit, filter, shp_name, sme
 #' @export
 tmapShape.SpatRaster = function(shp, is.main, crs, bbox, unit, filter, shp_name, smeta, o, tmf) {
 	#tmapShape.stars(stars::st_as_stars(shp), is.main, crs, bbox, unit, filter, shp_name)
-	if (!requireNamespace("terra")) stop("terra package needed", call. = FALSE)
+	rlang::check_installed("terra")
 	
 	#if (!inherits(bbox, "bbox")) bbox = sf::st_bbox(bbox)
 	
diff --git a/R/tmapTrans.R b/R/tmapTrans.R
index f0c7fd08..e2559d5e 100644
--- a/R/tmapTrans.R
+++ b/R/tmapTrans.R
@@ -189,7 +189,7 @@ tmapTransCartogram = function(shpTM, area, ord__, plot.order, args) {
 		
 	x = sf::st_sf(geometry = s, weight = area, tmapID__ = shpTM$tmapID)
 	
-	if (!requireNamespace("cartogram")) stop("cartogram pacakge needed", call. = FALSE)
+	rlang::check_installed("cartogram")
 	
 	if (args$type == "cont") {
 		shp = suppressMessages(suppressWarnings({cartogram::cartogram_cont(x, weight = "weight", itermax = args$itermax)}))
diff --git a/R/tmap_animation.R b/R/tmap_animation.R
index 191d522e..5034acac 100644
--- a/R/tmap_animation.R
+++ b/R/tmap_animation.R
@@ -57,9 +57,9 @@ tmap_animation <- function(tm, filename = NULL, width = NA, height = NA, dpi = N
 	
 	# check system requirements
 	if (gif) {
-		if (!requireNamespace("gifski", quietly = TRUE)) stop("Package gifski is required for gif animations but not installed.") 
+		rlang::check_installed("gifski", reason = "for creating gif animations.")
 	} else {
-		if (!requireNamespace("av", quietly = TRUE)) stop("Package av is required for ffmpeg animations but not installed.") 
+		rlang::check_installed("av", reason = "for ffmpeg animations")
 	}
 	
 	if (is.na(dpi)) dpi <- .tmapOptions$output.dpi.animation
diff --git a/R/tmap_icons.R b/R/tmap_icons.R
index d00d4267..77fad3a2 100644
--- a/R/tmap_icons.R
+++ b/R/tmap_icons.R
@@ -86,32 +86,28 @@ marker_icon <- function() {
 
 # fix.borders is needed to prevent that right-hand side and bottom edges disappear
 pngGrob <- function(file, fix.borders=FALSE, n=NULL, height.inch=NULL, target.dpi=NULL) {
-	if (!requireNamespace("png", quietly = TRUE)) {
-		stop("png package needed for this function to work. Please install it.",
-			 call. = FALSE)
-	} else {
-		pu <- is_path_or_url(file)
-		if (is.na(pu)) {
-			stop(file, " is neither a valid path nor url", call.=FALSE)
-		}
+	rlang::check_installed("png", reason = "for this function to work.")
+	pu <- is_path_or_url(file)
+	if (is.na(pu)) {
+		stop(file, " is neither a valid path nor url", call.=FALSE)
+	}
 		
-		if (!pu) {
-			tmpfile <- tempfile(fileext=".png")
-			download.file(file, destfile=tmpfile, mode="wb")
-			file <- tmpfile
-		}
+	if (!pu) {
+		tmpfile <- tempfile(fileext=".png")
+		download.file(file, destfile=tmpfile, mode="wb")
+		file <- tmpfile
+	}
 		
-		x <- png::readPNG(file)
+	x <- png::readPNG(file)
 		
-		if (fix.borders) {
-			if (dim(x)[3]==3) {
-				x <- array(c(x, rep(1, dim(x)[1]*dim(x)[2])), dim = c(dim(x)[1], dim(x)[2], dim(x)[3]+1))
-			}
-			x2 <- add_zero_borders_to_3d_array(x, n=n, height.inch=height.inch,target.dpi=target.dpi)
-			rasterGrob(x2, interpolate=TRUE)
-		} else {
-			rasterGrob(x, interpolate=TRUE)
+	if (fix.borders) {
+		if (dim(x)[3]==3) {
+			x <- array(c(x, rep(1, dim(x)[1]*dim(x)[2])), dim = c(dim(x)[1], dim(x)[2], dim(x)[3]+1))
 		}
+		x2 <- add_zero_borders_to_3d_array(x, n=n, height.inch=height.inch,target.dpi=target.dpi)
+		rasterGrob(x2, interpolate=TRUE)
+	} else {
+		rasterGrob(x, interpolate=TRUE)
 	}
 }
 
diff --git a/_pkgdown.yml b/_pkgdown.yml
index 5f8581c0..35028441 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -3,6 +3,3 @@ template:
   bootstrap: 5
   bslib:
     primary: "#5f8640"
-
-development:
-  mode: auto