diff --git a/lib/builder-utils.sh b/lib/builder-utils.sh
index e9e8d7b..687b880 100644
--- a/lib/builder-utils.sh
+++ b/lib/builder-utils.sh
@@ -141,7 +141,7 @@ convert_image() {
 	log_debug "Icon Wight: $wight < Hight: $hight"
 	convert $src -colorspace RGB -resize x160 \
 	    -size 160x160 xc:white +swap -gravity center  -composite \
-	    -modulate 110 -colors 256 $OUTPUT_DIR/resize.png
+	    -modulate 110 -colors 256 png8:$OUTPUT_DIR/resize.png
 	builder_check_error "converting image"
     elif [ $wight -gt $hight ] ; then
 	# Its wider so force 160x and let imagemagic decide the right hight
@@ -149,14 +149,14 @@ convert_image() {
 	log_debug "Icon Wight: $wight > Hight: $hight"
 	convert $src -colorspace RGB -resize 160x \
 	    -size 160x160 xc:white +swap -gravity center  -composite \
-	    -modulate 110 -colors 256 $OUTPUT_DIR/resize.png
+	    -modulate 110 -colors 256 png8:$OUTPUT_DIR/resize.png
 	builder_check_error "converting image"
     elif [ $wight -eq $hight ] ; then
 	# Its scare so force 160x160
 	log_debug "Icon Wight: $wight = Hight: $hight"
 	convert $src -colorspace RGB -resize 160x160 \
 	    -size 160x160 xc:white +swap -gravity center  -composite \
-	    -modulate 110 -colors 256 $OUTPUT_DIR/resize.png
+	    -modulate 110 -colors 256 png8:$OUTPUT_DIR/resize.png
 	builder_check_error "converting image"
     else
 	# Imagemagic is unable to detect the aspect ratio so just force 160x160
@@ -164,7 +164,7 @@ convert_image() {
 	log_debug "Icon Wight: $wight unknown Hight: $hight"
 	convert $src -colorspace RGB -resize 160x160 \
 	    -size 160x160 xc:white +swap -gravity center  -composite \
-	    -modulate 110 -colors 256 $OUTPUT_DIR/resize.png
+	    -modulate 110 -colors 256 png8:$OUTPUT_DIR/resize.png
 	builder_check_error "converting image"
     fi