diff --git a/lib/debootstrap.sh b/lib/debootstrap.sh
index 6af0db9595..30dc27356e 100644
--- a/lib/debootstrap.sh
+++ b/lib/debootstrap.sh
@@ -825,8 +825,13 @@ create_image()
 			cd ${DESTIMG}
 			if [[ -n $GPG_PASS ]]; then
 				display_alert "GPG signing" "${version}.img${compression_type}" "info"
-				[[ -n ${SUDO_USER} ]] && sudo chown -R ${SUDO_USER}:${SUDO_USER} "${DESTIMG}"/
-				echo "${GPG_PASS}" | sudo -H -u ${SUDO_USER} bash -c "gpg --passphrase-fd 0 --armor --detach-sign --pinentry-mode loopback --batch --yes ${DESTIMG}/${version}.img${compression_type}" || exit 1
+				if [[ -n $SUDO_USER ]]; then
+					sudo chown -R ${SUDO_USER}:${SUDO_USER} "${DESTIMG}"/
+					SUDO_PREFIX="sudo -H -u ${SUDO_USER}"
+				else
+					SUDO_PREFIX=""
+				fi
+				echo "${GPG_PASS}" | $SUDO_PREFIX bash -c "gpg --passphrase-fd 0 --armor --detach-sign --pinentry-mode loopback --batch --yes ${DESTIMG}/${version}.img${compression_type}" || exit 1
 			else
 				display_alert "GPG signing skipped - no GPG_PASS" "${version}.img" "wrn"
 			fi