diff --git a/lib/harden.sh b/lib/harden.sh
index fc0f6e5..699b520 100755
--- a/lib/harden.sh
+++ b/lib/harden.sh
@@ -139,7 +139,7 @@ function set_timezone_if_defined {
       if [[ -f "/usr/share/zoneinfo/$timezone" ]]; then
         echo "set timezone to $timezone ..."
         sudo ln -fs "/usr/share/zoneinfo/$timezone" /etc/localtime
-        dpkg-reconfigure -f noninteractive tzdata
+        sudo dpkg-reconfigure -f noninteractive tzdata
         echo OK
       else
         echoerr "unkown timezone: <$timezone>, please edit <$HARDEN_CONFIGFILE> and change to a correct value" && exit 98