--- orig/addtogroup
+++ mod/addtogroup
@@ -46,5 +46,5 @@
 if ! getent group -- "${group}" \
     | sed --expression='s/^\([^:]*:\)\{3\}//;s/,/\n/g' \
     | grep --quiet --fixed-strings --line-regexp -- "${user}"; then
-    adduser -- "${user}" "${group}"
+    adduser --quiet -- "${user}" "${group}"
 fi
