diff --git a/letsencrypt-auto b/letsencrypt-auto
index 514f03f46..cfc830c9f 100755
--- a/letsencrypt-auto
+++ b/letsencrypt-auto
@@ -15,12 +15,13 @@ VENV_BIN=${VENV_PATH}/bin
 
 if test "`id -u`" -ne "0" ; then
   if ! type sudo &>/dev/null; then
-    function sudo (){
-      args=("$@")
-      for i in "${!args[@]}"; do
-        args[$i]="'$(printf "%s" "${args[$i]}" | sed -e "s/'/'\"'\"'/g")' "
+    sudo() {
+      args=""
+      while [ $# -ne 0 ]; do
+        args="$args'$(printf "%s" "$1" | sed -e "s/'/'\"'\"'/g")' "
+        shift
       done
-      su root -c "${args[*]}"
+      su root -c "$args"
     }
   fi
   SUDO=sudo