diff --git a/letsencrypt-auto b/letsencrypt-auto
index d163998aa..e14b099a9 100755
--- a/letsencrypt-auto
+++ b/letsencrypt-auto
@@ -14,7 +14,15 @@ VENV_PATH=${VENV_PATH:-"$XDG_DATA_HOME/$VENV_NAME"}
 VENV_BIN=${VENV_PATH}/bin
 
 if test "`id -u`" -ne "0" ; then
-  SUDO=sudo
+  if type sudo &>/dev/null; then
+    SUDO=sudo
+  else
+    args=("$@")
+    for i in "${!args[@]}"; do
+      args[$i]="'$(printf "%s" "${args[$i]}" | sed -e "s/'/'\"'\"'/g")' "
+    done
+    exec su root -c "$0 ${args[*]}"
+  fi
 else
   SUDO=
 fi