diff --git a/letsencrypt-auto b/letsencrypt-auto
index e14b099a9..514f03f46 100755
--- a/letsencrypt-auto
+++ b/letsencrypt-auto
@@ -14,15 +14,16 @@ VENV_PATH=${VENV_PATH:-"$XDG_DATA_HOME/$VENV_NAME"}
 VENV_BIN=${VENV_PATH}/bin
 
 if test "`id -u`" -ne "0" ; then
-  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 ${args[*]}"
+  if ! type sudo &>/dev/null; then
+    function sudo (){
+      args=("$@")
+      for i in "${!args[@]}"; do
+        args[$i]="'$(printf "%s" "${args[$i]}" | sed -e "s/'/'\"'\"'/g")' "
+      done
+      su root -c "${args[*]}"
+    }
   fi
+  SUDO=sudo
 else
   SUDO=
 fi