--- /usr/share/univention-samba4/scripts/create_spn_account.sh.orig	2016-03-04 08:37:09.534230430 +0100
+++ /usr/share/univention-samba4/scripts/create_spn_account.sh	2016-03-04 09:17:42.952102480 +0100
@@ -71,2 +71,6 @@
 				spn_account_name="${2:?missing argument for samaccountname}"
+				if ! [[ $spn_account_name =~ ^[A-Za-z0-9.\-]+$ ]]; then
+				    echo "Only numbers, letters, dots and dashes are allowed to be used in samaccountname."
+				    exit 1
+				fi
 				shift 2 || exit 2